Some Interesting Stuff...

Dura Ace 7800 > 7900??? - Looks like Cervelo Test Team, the team who actually BUYS their own grouppos (so that they can use what they LIKE), thinks 7800 Dura Ace is BETTER than the 7900. Apparently, the 7900 just doesn't shift that well in their new S Cervelo frames since it has some funky cable routing. In fact, I even remember reading, a while back, that a cyclocross woman pro also was also sticking to 7800 since it handles the mud better.
http://www.cyclingnews.com/tech.php?id=/photos/2009/tech/features/ronde_van_vlaanderen109/RVV_Cervelo_S2_RD

http://www.cyclingnews.com/tech.php?id=/photos/2009/tech/features/ronde_van_vlaanderen109/RVV_Cervelo_Hammond_bar