There is SO much strategy in trying to win this race. If one goes all out to get in yellow and stay there, the whole team become a target and folks who might 'help' at one point will cease helping.
Any of the top 3 in Astana (as well as 2-3 others) are capable of trying to win, and it is not clear yet that Armstrong can beat Contador.
There is no use in wearing one's self out when there are no major challenges to overall position. The point is to win in Paris, not to be as macho as possible.

It mat well come down to who is feeling strongest in the Alps...and *IF* Armstrong, Contador & Leipheimer are all still within 10-15 seconds, it will be very interesting! Armstrong always wants to win, but Contador would love to prove HIS win was no fluke, and Leipheimer...and Cadel Evans and a couple others have never won.

I personally look for the 1st day in the Alps to be a test to see who is ready...and then 2 stages of "Ok, lets go SEE who is best!"