JP is being done by Universal. Either Spielberg reached some agreement or they just curbed his rhetoric.
But why would they not release these what you call "huge catalog titles"? They have already released plenty of good movies, and they are continuing to. There's over 400 movie titles on both HD DVD and Blu-ray, some titles shared.. and other Blu-ray exclusives that are available on HD DVD due to region free titles. It isn't going to just poof one day and disappear. There are great multi-million dollar box office movies on both sides.
Why? Because they want to capture as large of a release as possible and there aren't enough prospective buyers today. The same reason Disney (and others) haven't released their largest titles on BD. Universal was put in the position of trying to carry the load for HD-DVD earlier (and this is still true today to a degree), so they've had no choice but to release many of their best catalog titles. In other words, if the studios release their biggest titles today on HD-DVD, there would only be a very limited amount of potential buyers since the format only has a small amount of players in the field (compared to BD and even more so to DVD). With this in mind, they know they only have a one time shot at a big HD release, and as I'm sure you know, the first week or two of the release is where they really make their money. Releasing once on one format and then later on another doesn't yield the same results... With that said, it makes a lot more sense for them to wait a while for increased adoption before rolling out their biggest titles.
This is why it's pretty unlikely at this point (given the dismal state of HD-DVD) that you'll see the remaining exclusive studios release any of their big catalog titles exclusively on HD-DVD since they know the switch over to BD is imminent. My guess is you'll see all the studios releasing the bigger titles during Q4 of this year on BD, with some limited support for HD-DVD as well to please those adopters for a short while longer before the format is completely dropped.