I've started a TextMate Wiki to record some of the useful information from the mailing list and other sources regarding TextMate 2.  

Check it out at: http://www.matewiki.com.  

Since it's a real Wiki, any one can feel free to add information.  My goals are to keep it a lean development resource and to prevent repeated information from other sources of TextMate documentation.  Please give it a look and let me know what you think, if you are interested.