Why was FireTray created?
I was a fan of FireTray, using it (as most other users) with Thunderbird. Recent versions had minor issues. And as I was interested in addon development, I proposed to re-write FireTray using js-ctypes. This would eventually help get rid of the inconvenience implied by the rapid release process on XPCOM addons. My proposition was accepted.
What's next for FireTray
As of march 2012 (release date of the first js-ctypes version), I'd be happy to rest a little, and not spend much time on new features for a while :-)
It would be nice if all tray icon addons could unite to build a definitive, most powerful, unique tray icon addon. But before that happens, if someone feels like implementing the Windows counterpart, it would be fun to integrate it with this Linux version.