On the clearances. I have 4-5mm clearance on fork on my 2012 c59 running 25mm paves or 25mm veloflex on da climcher wheels. Same clearance on 25 mm Vitoria tubs on enve 3.4. So it's not just 2014 c59s that have the clearance.
@Caleido: That's interesting. I just double checked some measurements. I have my 2011 C59 and a 2014 C59 in front of me. I am using a pair of Campy Bora Ultra 35's with a pair of Veloflex Arrenberg 25mm tires mounted. To measure the clearance I use an Allen key inserted between the tire and the fork or seatstays, all the way through and see if I can move it from one side of the rim to the other, like a wand over the tire. Let's call it the "wand test". If it passes over cleanly, great. When it takes some wiggling to pass it through, that's the limit.
For the 2011 C59, the front clearance is 2mm (snug); the rear is 2mm.
For the 2014 C59 in front of me, the fork is different (I believe it to be a C60 fork, and the clearance is an easy 3mm, 4mm with a little rub, so closer to 4 than 3). The rear, after remeasuring, is actually a little tighter than my 2011 C59 and I could really only fit a 1.5mm Allen key in there for the "wand test". The same exact wheels were put in each frame to come up with these clearances.
So, I would say the C59 up until 2014 has the same clearance between the tire and the rear seatstays... the slight difference I measured being due to manufacturing/assembly tolerances. But for the front, the 2014 C59 has markedly more clearance.
I guess in conclusion, you'd better make sure whatever tire/rim combination you want to use, make sure it will fit the frame. The C60 should have ample clearance both front and rear, for 25mm tires at least.
Here's a couple pics of the fork that came with the 2014 C59 frame... C60 fork?? I think it is. It's certainly not a fork I've seen on any C59 until now.
Quick Update: 4/1/2014: After looking at @Geca's pic of his newly delivered C60, the fork I picture below is slightly different. The leading edge of the blades is a little more sculpted on @Geca's. Yet the one pictured below does in fact to be the same as shown on the Colnago website for the C60's. Perhaps they refined them a bit to shave off a few grams before final production runs.