While the release of "Transformers" has given HD DVD a much needed boost, the format is still lagging behind Blu-ray in regards to movie sales. According to a report by Home Media Research, Blu-ray movies outsold HD DVD by almost 2-to-1 in the U.S. during the first nine months of 2007.
Blu-ray DVD titles outsold rival HD-DVD titles by almost 2-to-1 in the first nine months of the year, but analysts expect additional HD-DVD support and new hit releases to "transform" the high-definition DVD battle score in the fourth quarter.

Home Media Research, a division of Home Media Magazine, said on Tuesday total U.S. sales of Blu-ray discs, using a Sony Corp -backed technology, totaled 2.6 million units from January 1 through Sept 30, versus 1.4 million HD-DVD discs sold.
These numbers are still quite small, especially when you consider that more than 8.3 million "Transformers" DVD's were sold in the first week alone. Unfortunately, high-def sales probably won't come close to these numbers until there is one clear winner. If you'd like to read more, the entire article can be found here.