Then why didn't Warner wait for BD's Java and then release the title simultaneously in both formats?
Warner probably got sick and tired of waiting for Blu ray.
Yup, they're waiting for BD-J to be implemented.
Actually if you asked some people, they'll tell you the release of Blu ray is half-baked and premature. (I don't need to go back in time to recall that it's first releases in mpeg2 codec on BD25 was pathetic.) BD at this time is really not as mature as or at par with HD DVD in many areas: (1) PiP interactivity (2) Audio tracks (3) old mpeg2 video codec. Ofcourse (3) has raised a lot of debates in the first months of BD release and everything is settled now with most studios using VC1 and AVC/mpeg4. (Though Sony still insists on using mpeg2). Except for BD-J, the disparities between the two are really more a result of the implemetatiion choices made by Sony/BDA rather than a technical limitation, as both formats are excellent in their specsheets.
In the area of audio tracks, DolbyTrueHD is not mandatory on BD, but optional. For a supposedly NEXT GEN video format BD prefers not to use NEXT GEN audio codecs and prefers old PCM format. (Understandly coz that's a SONY/Philips licensed product, same with mpeg2 for which it has many patents.) Not that PCM is inferior or anything. In fact, DolbyTrueHD and DTS-HD are actually decoded into PCM in the player, so you can have them streaming via HDMI 1.3. The issue is more on storage efficiency than anything. And so you can understand why BD50 is necessary. For most films and practical HT use, storage is not a problem with HD DVD with VC1 and DTH. But it becomes a limiting problem when you start to use mpeg2 and PCM5.1, together or singly. Ofcourse studios are starting to release BD with the more advanced video and audio codecs. But it somehow leaves a bad taste in the mouth that had it not been for HD DVD's stunning performance on VC1 and DTH, BD would probably be feeding its markets with mpeg2 and stickng to PCM for a much longer time.
The final revelation is the BD-J interactivity facility that up to now is non-existent in BD discs. Not only that, because interactivity is also a hardware concern requiring dual video streaming (main feature film and the supplementary features) at the same time, the hardware player must have some dual video processing chips to support this. And sadly, only the PS3 supports this, no current standalone BD player can do interactive stuff even if the disc had BD-J. HD DVD players have this feature, both hardware and software, from day one.
The implication here is quite clear. Once BD-J is implemented (rumored to be within this year), BD users can expect to double dip on new releases with this facility if they want it. More importantly, for non-PS3 users, they would have to upgrade their BD players with new BD players that have the right hardware support for Picture-In-Picture interactivity. This is not just a firmware upgrade issue. This is a hardware issue, unfortunately. If the player only has a single video processing chip, there is no way a firmware upgrade can make it interactive with PiP. (You can make the analogy with some TV sets with PiP features. These TV sets have DUAL TV tuners. You cannot have PiP with only one tuner.)
Warner is perhaps right to wait rather than come out with a simultaneous release and disappoint BD customers - the same way that their MI3 release on BD was a poor copy of their HD DVD release in terms of interactivity. I suppose all their BD releases are. Judging from the contents on the Matrix HD DVD release, it's way too rich not to employ interactivity - the one very distingushing feature of HD over SD DVD, apart from PQ and SQ. But Warner might just disasppoint their BD customers still since, even if their discs have BD-J, current standalone players don't, except for PS3.
(There's actually one more spec missing in BD at this time. Much has been said about their BD+ security on top of the AACS. This is baiscally what enticed Fox and Disney to join BD exclusively. But now not a single Blu Ray disc has BD+ because the specs have not been finalized yet. Fox and Disney apparently are left holding an empty bag, as it were. Ofcourse, BD+ will be implemented sooner or later. Just like BD-J. But such product lapses in the promises you see with the BD specs before it was released to me indicates the level of condescension SONY et al has for its customers. Compare that with HD DVD that has all the promised features from day one.)
Pardon the excess. Just my thoughts.