We hit some last-minute hiccups in testing that prevented the release on Wednesday, which were discovered while testing updating our own sites (e.g. toolset.com). These are very large complex sites with lots of customisations, and revealed some edge-case issues which are unlikely to affect 99% of people, but we nevertheless need to fix them before releasing, which means a few more days.
However, the likelihood is that these won't affect you and the site you have in development.
I'd suggest you start using the release candidates that are available from the beta channel of your downloads page (wp-types.com/account/downloads), which are very close to what the final versions will look like.