I feel its because there are many more BR machines out there than the HDDVD camps wants you to think. (can you say ps3)
I also think people are seeing who is behind what and just glancing at articles in the paper that are swaying them(blockbuster goes br; target goes br).
BR still has more titles that can be purchased to date, and now that Fox will be back in it this fall, its looking bright.
The other issue is new releases. More are on BR than HDDVD, sure Univ is realeasing some of their old movies, but many arent worth buying IMHO.
The new releases that come out on both usually show that the BR edition sells more than the HDDVD. On Amazon right now the BR 300 and BR Shooter are outselling the HDDVD counterparts.
The PS3 has begun outselling the xbox360 with the price drop, so I think the number of BR movies buyers is going to increase more. As stated the PS3 was a trojan horse, many gave it hell for a slow start but its sold over 6mil now and is picking up speed. This means that many more BR players out there so in the long run Sony is going to come out as the smart one for the "trojan horse".
All we need is for Univ to see this(not that many of their new releases have been great) and go neutral.