Wow, great advice from everyone, thank you. I still find it a little counter-intuitive that a more powerful muscle won't translate to more bike power, but I think I'm starting to understand specificity. It still drive me nuts though when I ride with people who have a year or two less experience than me, and still humble me.

Some advice on this subject from a Triathlete:

-------- Yoga --------
Like one of the repliers said: Yes, Yoga helps alot, if its REAL Yoga. There are 4 big types of Yoga I know of: Astanga, Vinyasa, Yin and Hatha, so lets go over them and their helpfullness.

Astanga: Astanga I've done in the past for 4 months. Its stretching, HARD stretching with lots of effort and requires a fit body todo it and one gets sweaty as hell. Good for generally combining stretching with muscle workout as some poses require a buttload of strength, like hand stand, bridge, etc. Its REALLY good if youre pressed for time and want a supplementive sport for your cycling and want a generally good cardio+stretch+workout all in one. 90minutes of pain if done right, and your clothes STINK afterwards and I do mean STINK, cause of all the garbage that got evicted into your sweat while doing it. I kid you not, that actually works or at least I can't recall any other sport, where my clothes stunk so much after a workout! And one feels supergreat and relaxed after a session. The most manly Yogaform, but its not without limits of usage: Don't do it as a triathlete cause stretching the achillis is either bad for cycling or running, but I can't remember which one it is. Astanga also don't mix well with other types of Yoga. Its killer on its own and a DEFINATE cardio workout for winter fx.

Vinyasa: Kinda like Astanga but not so extreme in the raw power, full force ahead stretch. Its hard still but kinda "Astanga light", haven't done it much so can't say much concrete about it but it still belongs in the "Power Yoga" category where Astanga of cause is too.

Yin: Yin is stretching and not as hard a workout as the above. But it takes ALOT of time todo right and it really helps, especially TT cyclists or people with lower back problems. The purpose of Yin yoga, which is a modern yoga form, is to stretch connective tissue, NOT muscles! Very important to understand. Mainly focused on the back and joint areas. Its a killer Yoga form for back problems, superb for avoiding tears and pulled ligaments if done right, though I can only confirm it really does wonders for a bad back.
Its basically a set of poses, generally speaking "packed" in 3 different "workout sets". Each set takes 60-70 minutes todo, so one alternates them, fx Set1 Tuesday, 2 Thursday and 3 Saturday. Every set is something like 15 odd poses of 4min non-stop stretching each, thats right 4 minutes! It means the muscles will get exhausted and then stop resisting the stretch after the first minute and then one can hit the connective tissue areas and really work on pulling them to regain the flexibility in fx the spine connective tissue, which is what causes most lower back pain. And sitting 2+ hours on a TT/Tri bike in the bars should convince anyone that Yin IS a good match for TT riders.

Hatha: This is where I will get strung up and hung by very flexible women. Hatha yoga, the few times, I've tried it, was the meditative yoga form, the quiet mental form of Yoga that often gives Yoga a bad rep among men, as "ya aren't sweating in there!". I've yet to master the usefullness of it, but in my open mind, there probably is some deeper meaning with it. Probably good as a free mental trainer if you need to focus on a big competition or need to get your act back in gear!
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Workouts:
A guy I know, who run the bike part of IM Relay teams in Pro-like times(4½hrs isch), recommends heavy squating, cause at some point there just will be these badass climbs, where umpf is needed. I'm not sure what he does exactly but he recommended a squat-heavy training program if only for supplementary use. Again if you wan't a strong back put in Deadlift as well. Benchpress only if you really wan't those strong wings but nice for balance I guess..

I agree on the cadance over power though it can't hurt to have a strong core, so maybe a good core program with squat as well or Astanga yoga in general plus some squat focussed training or maybe as a whole different kinda training, running up long stairs for minutes on end as intervals!
If you have back problems or are injuryprone, go for Yin yoga.

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My Intro, TT bike and Aero/WW Upgrade plan
"A forum post should be like a skirt - long enough to cover the subject material, but short enough to keep things interesting."

There is one of your motivational negatives - and possibly one of your biggest. This could well be the cause of your 'slump'.
The thing you must remember is that everyone is built differently. As a friend of mine says - We're all different cattle. Some guys just have a bigger engine or more outright power.
If you even focus for a second on someone who is better/bigger/faster than you then you have possibly forgotten one of - if not the most important assets in cycling.
Your brain. 'Race smart not hard' Ever hear that before? The number of times I've tried to prove how I'm just as strong as the next guy and have been dropped or had nothing left at the end is embarrassing. But whenever I raced smart and let others do the he-man thing I always managed a place or a win.

On the question of weights and yoga. I agree with nearly everything all the others have said. Both have a place in your life if you crave more than just cycling. I also like the idea of throwing in other disciplines like MTB (Which reminds me I must get out on my MTB - it's been over a year ).

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Don't let the truth get in the way of a good story......
Argon
CAAD9 6.78Kg
Supersix 6.78Kg

Weight training is also great if you want your guns to look lean and cut.

in my opinion weight training should target explosive movements to have more effectiveness. 3-4 sets of 5 reps at a moderate weight and explosive movements will help you explode a little bit better when covering a break or sprinting during that las part of the uphill finish. this also has the benefit of helping you keep you weight in check for most as you will need a more complex work out rutine to have considerable weight gains caused by hypertrophy. when i was in t&f during my early 20's i use to hit the gym no more than 2 times a week just to get some confidence in my power, and to get some testoterone boost. weight training if done correctly will help testosteron production which migh aleviate your blues. i my opinion there are ways that are more fun for strenght training than the gym, like pull up bars at the local park followed by some plyo training at the local stadium steps, and some push ups, followed by sit ups after an easy ride (2x25 sit ups and 2x25 push ups).