So I was at the Cervelo Dealer event these past couple of days, and I was actually able to ride one of their new S5 bikes, equipped with Sram Red, Mavic Cosmic Carbone SLs, and a 3T cockpit. Let me tell you, the bike is fast. I currently ride an S3, and the S5 is definitely a faster ride. Cervelo is about to/probably already has released a ton of information, but the basics are below.
Geometry: the geo now exactly matches the current R3/R5 line, in terms of stack and reach, as well as in terms of bike handling (same chainstay length, same seat and head tube angles).
BBright: the S5 will use a BBright bottom bracket, which they claim increases stiffness, minimizes weight, and is more aero than an outboard bearing system (due to a cleaner BB area).
Aero: Cervelo claims that the S5 has about 90 less grams of aerodynamic drag than the S3, which they estimate to equal about 9 free watts.
Weight: The top of the line frame will weigh about 990 grams, size 56, including seatpost clamp and rear derailleur hangar.
Availability: A VERY few will be available at the end of July, and a VERY VERY few will be in stores this week.
Some of the Garmin-Cervelo Team will be riding them at the Tour de France; Thor, DZ, and maybe a few others would be my expectation (Thor used the bike at the Norwegian national championships [2nd place, I think]). Thor's quote "Holy crap, this bike is fast!" That really says it all.