If betas are going to be released, I suggest one improvement: Scenes made in beta should have special "beta" tag, which will hide them from the main page. This will allow more "experiments" with elements through developing, because users of stable version wouldn't see scenes made in beta (if they wouldn't search "beta" tag, of course).
Saves made in the Betas aren't openable in stable versions anyway, though they appear when searching you will get an error about an incompatible version when you try to open it in a stable release.
savask As ad said, they are actually in the game, just hidden because they didn't work correctly. If you look at the source code for version 35, you'll see it's there.