Lead out trains
It occurred to me that every man and his dog (no offence Cadel) tries to get on Cavendish's rear wheel in the 'final'. Why don't HTC put a man behind Cav to keep them off? Aside from the obvious (one less man to pull on the front), I can't see a downside. He would obviously have to hold the wheel well and have pointy elbows. Big Bert Grabsch in his early season shape (think Ulrich off season) would be ideal!
As Cav accelerated, the 'sweeper' would just hold his line, thus forcing other sprinters to follow other wheels. Someone like Velits could do a turn say 5-4 km out then tuck in behind Cav. He did something like this on an earlier stage but got back in the paceline in front of Tony Martin I think.
Have I been watching too much TdF?