If you're a Netflix customer you're already familiar with the existing 28-day "window" between a movie's release on DVD and when the DVD is available for delivery — the idea is people impatient to see the movie will break down and buy the DVD, boosting DVD sales. It's a silly idea, and it's about to get sillier: All Things D reports Warner Brothers will double the window to 56 days in a new deal with Netflix, Blockbuster, and Redbox that'll be announced at CES. The goal is to bolster falling DVD sales while Warner and the rest of the studios get the new UltraViolet DRM-locker off the ground — eventually Hollywood wants everyone to buy UltraViolet movies from a variety of retailers and services, so don't expect these windows to go away.

What's unfortunate is that the last time the studios insisted on windows, Netflix was able to negotiate the rights to additional streaming content in return; this time it's apparently getting nothing at all, but signed the deal anyway. That's in sharp contrast to what happened between Netflix and Warner subsidiary HBO, which no longer provides wholesale discs to Netflix — by taking the deal with Warner, Netflix can't just go out and buy discs from another party like it's doing with HBO. We'll see if there's any good news behind this when we get to CES.