This is news because TextMate 2 has been the Duke Nukem Forever of the Mac nerd community for so long and also because of what open sourcing the project means to users.
This likely means we will never see a final TextMate 2 build, of the quality and polish that all TextMate users have come to hope for and in that respect this comes as saddening news.
I am personally torn — I supported TextMate 2 irrationally for much longer than I should have, while I stumbled along with TextMate 1.5. The thing is: TextMate 1.5 still works, and works fine for most of what I use it for, but with the changes to Mac OS X its age is showing in many spots. The alpha builds of TextMate 2 have been nice, but buggy and mostly unusable even for a non-coder like me.
Unlike so many other people, I haven’t switched to Sublime Text 2 or Chocolat ((The latter because the name reminds me of a bad movie.)) — no I decided to jump fully into Coda 2 and Writer. I haven’t missed TextMate since making the change a while back, but I always held out hope to switch back to it.
As for TextMate 2 and its future , this presents an interesting crossroads for the app. Either it will languish in development and interest and become but a blip in Mac nerd memory, or it will be rapidly worked on with the potential to become the best open sourced text editor for the Mac.
The latter is probably not likely, but I still irrationally hold out hope that the latter is what occurs.