In a surprising move, ABC announced that Grey's Anatomy will officially move to Thursdays at 9 p.m. beginning next fall.

The shift triggers a brutal showdown for the Thursday 9 p.m. slot, long considered one of the most prestigious in prime time. Meredith and company will be taking on CBS' smash hit CSI: Crime Scene Investigation, as well as NBC's new comedy-drama Studio 60. CSI is presently the top-rated scripted show on TV.

The move was the most drastic of a laundry list of changes issued by ABC, which nixed all but two of its sitcoms and announced 15 new series - six comedy, six drama, three reality - for 2006-07. The network plans on using both Grey's Anatomy and its (now-former) Sunday lead-in, Desperate Housewives, to bolster new shows:

• Brothers & Sisters, a drama about siblings forced to take over the family business after their father dies, stars Calista Flockhart and will take over the coveted 10 p.m. Sunday slot behind Housewives.

• Six Degrees, a high-concept relationship drama co-created by J.J. Abrams (of Lost and Alias fame), and previewed during the Grey's Anatomy season finale, will follow Grey's on Thursdays at 10. It follows six New Yorkers who don't know each other (yet) but are indirectly changing each other's lives. It stars Erika Christensen, Hope Davis, Campbell Scott and Bridget Moynihan, among others.

Needless to say, we'll tune in whenever we need to. Thursday, Sunday, what does it matter? All we care about is watching Dr. Burke recover while Meredith chooses McVet (or that other guy who wants her).

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.