A little more waiting, a little less waiting. That's just how this game goes.
Bad news first: Overture's space-set sci-fi/horror Pandorum has been bumped back a fortnight to September 18th, now putting it opposite the horror comedy, Jennifer's Body, written by Diablo "Juno" Cody and starring Megan Fox. I haven't heard the best things through the grapevine about either film, but I suppose it's slightly less competition than Carriers and Gamer on the 4th.
Better news then? Summit slasher Sorority Row has brought itself up three weeks from October 2nd to September 11th, although it now contends with Kate Beckinsale thriller Whiteout (which probably won't draw as much, now that I think about it). I'm not sure who's going to fill that prime October 2nd spot, or maybe Scorsese's Shutter Island is going to score across more demographics than I had previously considered.
Seriously, though, from the last weekend of August with Halloween 2 and Final Destination 4 on through Halloween, it looks like there'll be no shortage of genre offerings around this fall (even with Lionsgate's Daybreakers moving back to January 2010 and Paramount's long-shelved Case 39 disappearing yet again).