Hits Daily Double has released its initial prediction for the US album chart this week.  This is what they had to say:

Britney Spears’ Blackout album will debut on next week’s HITS chart at #1, with an impressive total that could threaten 400k. As it is, the beleaguered grown-up teen diva looks on target to sell between 350-380k, which ain’t bad at all.

The album is also #1 on most of the international iTunes stores, including the UK and US stores.