Here's my take.....Hillary should have more on her mind than 2008.
Step 1 - She needs to win re-election as senator in 2006 - and that could be a tall order if Rudy runs against her. This is where Giuliani can hurt Hillary the most and help the Republicans the most.......very high profile campaign, very expensive and, most importantly, her positions would become more evident to the electorate.
Step 2 - Along about the time of the 2006 election, Vice President Cheney steps down for a "u-pick-it" reason. Condi is chosen as VP. This does 2 things.....it will lessen the last two years as a lame duck status for GWB (Somebody has to be a threat to exact favors or "pounds of flesh" in Congress. It couldn't be Cheney since we know he won't run.). And, it gives Condi enough time to establish bona fides as a presidential candidate in 2008. So..........
If Hillary loses in 2006, she will be greatly diminished as a candidate. If she holds on to her senate seat, she will be tarnished and Condi will thump her badly. Finally......
Watch out for Bill Richardson or Evan Bayh....one of these gentlemen have every bit as good of a chance of being the dems nominee in 2008 as Hillary.
Just my take......
Lando 
Hillary knows the political landscape has changed dramatically.
The political ground under her prez ambitions has shifted, and she is on very shaky ground.
I, for one, am not worried about any Dem candidate they would dig up. Losers, losers, losers.
Condi would have to establish some very serious conservative credentials ....as far as we know, she is not pro-life....and that is a must for a Republican candidate. She is out of the running is she so much as hints that abortion might be somebody's (gag) right.
I don't think Giuliani will run against Hillary in 2006. He just started an investment-banking firm, and I doubt his partners would have gone for it without a promise of 2 years of relatively undistracted commitment.
"Step 1 - She needs to win re-election as senator in 2006 - and that could be a tall order if Rudy runs against her."
Exactly. I would argue, though, that if we can't get Giuliani or Pataki to challenge her, we shouldn't bother. Running another weak candidate (like Lazio) just gives her a platform for publicity, and she will be able to exploit her "landslide" victory to win the nomination.