Please check the release notes and the feature list for details. Overall more than 139 issues have been fixed since the last 2.x series release. The most notable changes are probably the dropping of xine support upstream (gstreamer is used now for all video/audio on Linux) and the introduction of subtitle support.
I have uploaded a new Miro 3.0 Debian package to unstable recently (which have been a delayed a bit due to Debian server issues), by now it should be available from most mirrors. Let me know if there are any issues...
It's been announced at quite a few places, so you probably already heard about it: Miro 2.0, the new major release of the cross-platform Internet RSS audio/video aggregator and player has been released.
Miro is available for Linux, Windows, and Mac OS X, the new release on Linux now features a "native" GTK+ widgets UI (instead of the Mozilla-based HTML widgets of earlier versions) and supports both a xine, as well as gstreamer renderer (for audio and video).
I won't even attempt to list all the improvements and new features, please check the release notes and the feature list for details. Overall more than 670 issues have been fixed since the last 1.2.x series release.
You can also watch this video (Ogg Theora, 10 MB) for a short introduction in Miro 2.0.
Finally, I have uploaded a new Miro 2.0 Debian package to unstable yesterday, by now it should be available from most mirrors. For Debian we're defaulting to xine at the moment, but please consult README.Debian if you want to switch to the gstreamer backend.
Please test the new release extensively so the few remaining issues (if any) can be ironed out soon...