FYI, the "experimental" thing is a community thing, not really a technical judgement. Since this is our first Python 3 release, we want to have some space to make changes between 1.5 and 1.6 that we otherwise would avoid because of our strong backwards compatibility promise. The "experimental" label is about giving ourselves that room and not surprising users if there do have to be changes in the way Py3 support works between 1.5 and 1.6.

Technically, however, it's pretty rock-solid. I'll be launching a site built on Py3/1.5 is about two weeks, and aside from constantly forgetting to `print(...)` instead of `print ...` it's been surprisingly smooth sailing.