Quite a few people have been asking about the status of Ardour3. The short story is that we are getting closer to a beta release every day, in large part thanks to the outstanding work of Carl Hetherington and also a small group of very dedicated and helpful testers. Almost of the basic functionality planned an initial release is in place, which means that MIDI recording, playback and editing is in reasonable shape for use and that the audio side has too many improvements to count or even list here in this modest posting.
We maintain a "roadmap" that shows the current bugs slated to be fixed before a beta release - these will not all be fixed, and they vary from the mildly annoying to the absolutely critical. At the moment, the Roadmap-o-meter says we are 80% done. In addition to this list of officially tracked bugs and issues, there are 4 or 5 significant areas that need some attention before we are ready for a beta release.
Finally, there is the biggest issue that blocks a beta test: freezing the format of the ardour3 session file. We are very close to doing this, but there are two areas of concern where we want room for changes for a little while longer. The goal is to ensure that once people start testing Ardour3 beta 1, any sessions they create will continue to be loadable by later versions without us developers having to hack in ugly back-compatibility nonsense.
As usual, we're not going to provide an estimated date for a release of Ardour3 beta1, but it is getting pretty close now. I would even go so far as to say that those who don't mind potentially losing test sessions but are willing to give us feedback on both workflow and outright bugs could consider building from SVN at this point.