Types rocks my socks off. Thanks for an incredible plugin. I just wanted to second that The current version of Types (1.4) isn't saving custom meta entries when testing out WP 3.5 Beta 2. The specific version number is: 3.5-beta2-22241, which is the latest nightly build.
I'm sure you guys are hard at it making sure that it'll work, but figured it was at least worth mentioning.