Subsonic 4.4 was released in Feb 2011
Subsonic 4.5 was released in Aug 2011
Subsonic 4.6 was released in Dec 2011
Subsonic 4.7 was released in Sep 2012
As you can see, official releases are currently less frequent. Subsonic 4.7 brought a lot of news, plus some changed behavior and bugs, not surprisingly. The new version didn't fit everyone and the new bugs and sparse updates made people more likely to look for tweaked versions that fulfilled their needs and feature requests, that weren't implemented in the official version.
MadEvil started releasing a forked version in Mar 2012, I released another fork in May 2012. The previously popular Supersonic fork seems to have died at about the same time.

MadEvil does an "Original Subsonic + extra goodies" version that is kept up to date with the official code base. I gave up on that pretty early and re-wrote a lot of core logic from scratch to make it more efficient and adapted for music only so mine is more give and take (add some new features, remove others).
The community has therefore become more diverse. The majority probably still run the official release but there's certainly an interest in the forks.
The most common request is probably an interface overhaul (to HTML5, leaving Flash behind). The most common error reports are related to the technical difficulty of getting everything running, with all the possible sources of errors (transcoding setup, a somewhat shaky default database, failed Java updates...) but it's rarely expressed as a feature request. The way Subsonic is designed (using Java as a language and using external programs for transcoding) will make it more difficult to setup than a native program with a one-click installer. It's hard to avoid without redesigning some major concepts.
But if you ask somebody using Subsonic mainly for music and somebody else using it for streaming video to a handheld device, you'll get very different answers on top priority feature requests. That's why I'm fine with going in different directions, I don't think it's worth maintaining a product that tries to do everything. But everyone wouldn't agree on that either...
Anyway I dare to say that the keyword is HTML5 no matter who you ask. That would be the most asked for update.