The attached patch against 2.7 adds a new fixer to 2to3 that replaces deprecated unittest method names with the correct ones.
There are a few issues:
1) only the "safe" renamings are included; the assert[SameElements|ItemsEqual|CountEqual] and the  assert*Regexp*->assert*Regex* changes are missing;
2) unless 2to3 provides a way to specify a target version (e.g. 3.2 rather than just 3.x), the missing renamings can't be included;
3) the patch is against 2.7 but I'm not sure in what versions could/should be included, or if the fixer should (also|only) go on PyPI;
4) this fixer is useful from 3.1 to 3.2 too, is there a way to use it with 3.x versions only?
5) doc is still missing;