Those dates posted by BLT are general dates put out by the distributer (ingram micro) and are the same on a number of sites who just take the info and use it. I wouldn't worry about these dates... if one of the largest distributers of core duo 2s, ingram micro, is going to delay that long, chances are you won't be able to get them from somebody else significantly faster.
Those dates are merely carbon copy estimates and are not set in stone by any means. Chances are they'll ship well before those estimates, or they won't ship for anybody until those dates, one of the two.
If you are early in line in the queue, 0-50, I wouldn't worry.