Anyone here who KNOWS anything, such as being a Beta testor, has had to sign a Non-Disclosure Agreement
Anyone else is just guessing... my GUESS is that Adobe is concentrating on Win7 compatibility and, I hope, a 64bit version
It would be nice if a 4.2 update came out that included AVC-I support, as well as fixed some issues. Though I don't hold out much hope for that. Adobe has a history of making people pay for bug fixes with a new version.
Often, when an update is being worked on, little hints and clues appear in press releases and podcasts, usually cryptically placed and very vague. Sharp readers and viewers usually rush here with those tid-bits, asking for clarifications. As no one has posted any of these, it would seem that all work is on CS5 at the moment.
Does this preculde a CS4.2? No way, and maybe Adobe has just been tight-lipped about it. Still, with not even a whisper, I'd think that it would be unlikely. That said, as John points out - it's but a "guess."
I don't have any inside info, but it wouldn't surprise me at all if another update is in the works...one that includes AVC-I support, bug fixes, and maybe FCP export...and it wouldn't surprise me at all if it was released within the next few months.
Again, I haven't heard anything from anyone - just my guess...