Variety reports that the two remaining studios backing HD DVD could switch sides soon, ending the high-def format war instantly.

The trade has confirmed that Universal's commitment to backing HD DVD exclusively has ended. And Paramount has an escape clause in its HD DVD contract allowing it to release films on Blu-ray Disc after Warner Bros.' decision to back that format exclusively.

Neither studio is ready to throw in the towel immediately, however. Universal is committed to a series of promotions for the high-def format in coming months, and Paramount has said its current plans are to keep supporting HD DVD, which it backed exclusively in August and the deal was to run through this year.

Should Toshiba concede defeat on the format, the decision to drop HD DVD would be made for both studios. But Toshiba doesn't appear ready to do that.

But retailers may force the HD DVD camp's hand: They're unlikely to keep devoting premium shelf space to a dying format, and at this point, the odds are not in HD DVD's favor. With Warners' defection, only Paramount/DreamWorks and Universal remain in the HD DVD camp; Sony, Disney, Fox, Lionsgate remain ardent Blu-ray backers. Warner sister companies New Line and HBO are also shifting allegiance to Blu-ray.