AFAIK, the only development on YUI2 is to fix "significant" (ie, new and/or awful) bugs, and to remove forks and special code that was in place for deprecated browsers (ie, safari 1.0 stuff, mostly.)
All the new development is happening on YUI3.
I'm not an authority on the matter, of course, since I've only been on the team for -1 week ;)
AFAIK, the only development on YUI2 is to fix "significant" (ie, new and/or awful) bugs, and to remove forks and special code that was in place for deprecated browsers (ie, safari 1.0 stuff, mostly.)
All the new development is happening on YUI3.
I'm not an authority on the matter, of course, since I've only been on the team for -1 week ;)