I like it, I've used a few python frameworks, and I enjoy working with Web2py. It has quite a large community, though not as big as Django or rails. 3700+ members of the group on groups.google.com. Massimo (the guy who invented it, and teaches it) responds to a lot of the requests for support, and normally his answers are one-liners to solve whatever problem you are having (which 99% of the time are all documented features). I've been experimenting with it for a few weeks, and I'm finding myself able to answer most people's questions about it. The whole philosophy behind it is to have sane defaults, and default to being secure.
As far as freelancing is concerned, it will help to know Rails if you are planning on fixing rails apps or adding features, but if you are going to be building things from scratch, I'd say choose whatever framework you know best.
I like Web2py because it doesn't force me to make classes for my database items, database items are simply datasets. Also, I write my code once and it works on pretty much any database backend (including GAE) without changes.
People criticize it because it does things differently than every other framework, but I like that it does things differently - it makes coding a web-app pretty effortless.
So, if you are interested in Web2Py, use it. I think you'll like it.