The big 3 have been fighting for the top of the podium as usual. SRAM fired the first shots last year with Red. Super light weight, ceramic bearing options and the powerdome cassette were some of the features that made the old guard take notice. They became a player, not only on the Pro Tour but at the retail shops as well. At $2000 for the group set they are suddenly the bargain group (keep reading..) and everyone I know riding Sram, loves the double tap levers. The open rear derailleur cage design, makes it a nice option for cross as well.
Shimano introduced 2009 Dura Ace 7900 with all new shifters, hidden cables and IMHO the sweetest baddest looking crankset of the bunch. Not a cheap group by any measure (@ $2,700 for an 8 piece group), it appears to be a well thought out design based on their already excellent MTB group XTR. I don't love that it is not compatible with the 7800 group, but to quicken up the shifting, they needed to shorten the throws. I condsider it a necessary improvement, not a plan to screw the folks using the previous version.
Campagnolo answered with the 11 speed Super Record Group. This screams flagship all the way. Super light weight, lots and lots of carbon and titanium and a hefty price tag to boot ($3,200!!!!! for the 8-piece group). The shifting became quicker and more robust, the levers were redesigned to ofter more positions and the chain is an ultra narrow 5.5mm.
Personally, I'm a campy guy and although I have no immediate plans to run out and buy a Super Record kit, I have always enjoyed the rebuildable aspects of Campy, but I also love the thumb shifting and the overall shape of the levers. I also enjoy the mulitple shift capabilities, the super stiff but light braking, front derailleur trim and I get years and years out of cassettes and even chains with some minor maintanence. On my 2 Record 10 road bikes and my Centaur 10 cross bike, I expect nothing less than rock solid performance and silent drivetrains. Replacement stuff like cassettes and chains are a bit pricey, and the chain tool required is a bit of a scam (I get around this by using connex quick release links), but the stuff is made well and you can get replacement parts for Campy stuff from 20+ years ago with little difficulty.
What's your favorite groupset and why?