If you ever considered contributing to PyPy, but never did so far, this is a good moment to start! :-)
Recently, we merged the fast-forward branch which brings Python 2.7 compatibility, with the plan of releasing a new version of PyPy as soon as all tests pass.
However, at the moment there are still quite a few of failing tests because of new 2.7 features that have not been implemented yet: many of them are easy to fix, and doing it represents a good way to get confidence with the code base, for those who are interested in it. Michael Foord wrote a little howto explaining the workflow for running lib-python tests.
Thus, if you are willing to join us in the effort of having a PyPy compatible with Python 2.7, probably the most sensible option is to come on the #PyPy IRC channel on Freenode, so we can coordinate each other not to fix the same test twice.
Moreover, if you are a student and are considering participating in the next Google Summer of Code this is a good time to get into pypy. You have the opportunity to get a good understanding of pypy for when you decide what you would like to work on over the summer.