for those of you using rails 3, are you going to be using this rc candidate, or the ruby 1.9.1-p429. I've ran into a lot of issues using ruby 1.9.1 and are either fixed using ruby 1.8.7 or ruby 1.9.2 .. so just wondering ?
That said, I am using 1.9.1 in production (non-Rails project) and have had almost no issues so far, apart from a few libraries that had to be updated, but that was mostly minor issues (e.g. #methods returns strings in 1.8 and symbols in 1.9).
Might as well do it all at once, you know?