Oh, you didn't find it under the downloads tab? That's because it's now at our brand spanking old SourceForge files repository. It isn't as quick or clean as Google Code was, but it still has MD5/SHA1 hashes for you paranoid folks, it lets us organize by version, it has geographically distributed mirrors and it didn't cost me any freaking money. Get files from the 24.1.0 folder; the release notes are still at Google Code. Remember, only downloads have moved; everything else is staying at Google Code for the immediate future.
I am informed that Tenfourbird is indeed circulating a beta version of 24 too, and I'm delighted to see our anonymous builder in the Land of the Rising Sun has made the jump to the next ESR with us. It's just a coincidence that he uses SourceForge as well, by the way. Maybe.