I think we'll know for sure after this November.
Why?
First, of the few 'competitive' house/senate races out there are some where one or both candidates are making guns an issue (pro or con). For example in MI, iirc, redistricting has one anti-gunner making a big issue of 'gun saftey' (as the current push is called), and 'loopholes'.
If we see the good guys win these kinds of races, then that should be a sign that the AWB may die (even temporarily). If not, I'll lean toward the 'we're screwed' mentality.
Second, GWB will not spend political capital on this issue. He won't try to force a new AWB, but he won't veto/not sign one either. So the power to let it lapse lies in one or both houses of congress. Hence, November.
Oh, and it will take some [i]incredible[/i] feats of constitution bending for the FEDERAL government to actually ban CONTINUED POSESSION of any now-legal gun. But they could destroy the market for 'AW' type guns (by a total transfer ban with no grandfather clause), so only 'stock up' if you really need a 'full-featured' gun, not as an investment.