They might be waiting for Sony and the BDA to make them an offer. Honestly, what do they gain if they go to Blu-Ray without incentives? (Anyone who thinks Disney, Fox, Lionsgate, Universal, etc. got no incentives is seriously delusional.) No one is raking in money on HDM sales. Together Blu-Ray and HD DVD barely beat VHS.
Essentially Universal and Paramount are making HD DVD viable. If Microsoft actually lowered the price of the standalones we might have another good fight for a year. Personally I wouldn't recommend anyone touch a Blu-Ray player (other than the PS3) until the 2.0 standalones come out.