Drupal 7 Core is basically finished, save for a few bugs.  However, OGA uses a number of modules that go way beyond Drupal's core functionality, and not all of them are quite ready.

First and foremost is OGA2's idea of art collections.  For art collections to work, we need something called Node Reference, which is essentially a module that allows you to make a node (or a field inside a node) that just points to another node.  Without node references, there's no easy way to allow people to make collections of existing art.  Node References are a powerful enough feature that I'm guessing someone will make them work shortly after the Drupal 7 release.

Secondly, the Rules module provides automation of various functions when certain events happen, and it's what we use to award points to people when they comment, submit art, mark favorites, and so on.  Rules is mostly ready, but the UI is pretty arcane at the moment.  If worse comes to worse, I can automate these events with PHP code, but I'd rather stick with Rules if the option is open.

The Badges module is what we use to award people medals.  There's no evidence that any development has happened for the Badges module in Drupal 7, however I suspect the functionality wouldn't be too hard to duplicate if I had to.  Besides, Badges to some extent falls short of the functionality I'd like -- however, I'd prefer to patch their code with and submit updates rather than write it all from scratch.  That way, they'll maintain my changes for me. :)

Taxonomy Access Control is used to help administer permissions for varios pages on the site.  It's not ready yet.

There's an advanced forums module that makes our forums work better than the typical Drupal Forums module.  I don't know how necessary it will be, because I haven't really looked into Drupal 7's core forums module yet.

The biggest issue is the whole Node Reference thing.  Without that, I can't really even get started on the core functionality of OGA 2.0, since so much of it depends on being able to link from one node to another.  I can, however, get started on converting themockup into a real OGA2 theme, and working on a simple module to export our current art in XML format so that it can be easily imported into the new database.

Anyway, that's pretty much where we stand right now.  I figure that I'll handle the beta by having both OGA and OGA2 up at once, with a big warning on OGA2 that it's in beta and all data added to it will be erased and refreshed from the main site on a frequent basis.  The idea is that I'll expose it to enough people that I'll know when the community is generally satisfied that we've reached a stable state, and then we'll do the official switch.  We won't officially move to 2.0 until it can be done without any major loss of existing functionality.

Peace,

Bart