Let's just say my experience was less than perfect. Add to that language barriers and it is just a very hard project to work for.
Of course, projects like VLC and mplayer still get a lot of the credit for the hard work that FFmpeg is mostly responsible for.
On the other hand, once I compiled the libraries, I had no issues interfacing it with code in Visual C++ \C#. The source files are fairly clean and documented enough that I could mostly figure out what to do by looking at the code.
In the extreme, if everyone works on an independent fork, and never merges, we lose the benefits of building "team-sized" projects. But that does not seem what is happening here.
Perhaps some of the fixes from libav can be brought back into ffmpeg, but eventually people will want to standardize on one or the other, and if the libav folks are splitting off because they want improvement, revitalization, etc. and the old guard doesn't, then I suspect people will move to libav instead.
Similar issues happened in the past with xorg (where XFree86 was mismanaged and eventually the community had enough and decided to fork it and fix it) and with KHTML/WebKit (where Apple forked it and made so many improvements to it that WebCore/JavaScriptCore have replaced KHTML in most (all?) projects (including Qt). That split wasn't a philosophical/managerial split, mind you, but the end result was the same.
