Similar to their efforts with Blu-ray, the MPEG LA has announced plans to create a joint HD DVD patent license. At this point, the group has put out a call for patents that are essential to the HD DVD Standard.
MPEG LA, LLC, world leader in one-stop technology standards patent licensing, today issued a call for patents and patent applications that are essential to the HD DVD Standard in order to facilitate creation of a joint HD DVD patent license.

"Continuing in its mission to respond to the market's need for fair, reasonable, and nondiscriminatory access to patents essential to defined technologies, MPEG LA is pleased to accept an invitation to facilitate this effort so that users may have the benefit of a convenient marketplace licensing alternative to assist them with implementation of their technology choices," said MPEG LA Chief Executive Officer Larry Horn.
The MPEG LA will be accepting submissions through the end of June and currently plans to meet with essential patent holders in September. If you'd like to read more, the MPEG LA's entire press release can be found here (PDF).