What would be most beneficial, if you haven't done it already, is if you ran the code against your existing database with all the users, etc. Make an export, run through the upgrade and test it.
That will give us an idea of any scalability things to work on.
I'll be tagging the branch about once per week. When you are ready, I can make a tag shortly before your launch so you can launch on an official version.
We are still putting in several bug fixes per day. In a week or so, I'll start making tarballs for other people to try, but right now we still need "hands on helpers" that can help us fix problems.