Nice! How long does vim usually stay in beta? I'm not familiar with Vim's release cycle
There were 28 days between the announcement of 7.3a and 7.3, 46 between 7.2a and 7.2, and 7 between 7.1a and 7. It took 45 days to go from 7's first beta to stable release.
For many of these, there were several beta releases, so there's a good chance we'll see a 7.4b or 7.4c. I would say that it certainly won't take more than two months before 7.4 is released and probably will take less than a month.
You can sign up for vim-announce here: http://www.vim.org/maillist.php.
Sources: 7.3a: https://groups.google.com/forum/#!topic/vim_dev/lSlC6cUV5TY
7.3 https://groups.google.com/forum/#!topic/vim_announce/ZsAu_RU...
7.2a: https://groups.google.com/forum/#!topic/vim_multibyte/FVRKk5...
7.2: https://groups.google.com/forum/#!topic/vim_announce/LIlnHdk...
7.1a: http://vim.1045645.n5.nabble.com/Vim-version-7-1a-BETA-has-b...
7.1: http://tech.groups.yahoo.com/group/vimannounce/message/178
7: http://tech.groups.yahoo.com/group/vimannounce/message/161
7b (there was no 7a, apparently): http://tech.groups.yahoo.com/group/vimannounce/message/153
7.3 has more than 950 patches, that's too many! Time for a new (minor) release. The plan is to (1) improve Python support, (2) include a faster regexp engine and (3) include pending patches and fix bugs. A test version should be available end of May. The release happens when it appears to work well.