I'm hoping to roll a beta over the weekend or Monday. At the moment I'm just awaiting some very minor tweaks to the documentation resulting from our name change to "Open Architecture" - Vinod and Roberto have said they'll be get that done by the weekend. Neophytos is sorting through submitted patches and applying them when appropriate.
Workflow's in good shape in the sense that it works as well as it did in ACS 4.2 (a bit better, actually, I fixed a few minor problems with custom task panels, etc). It provides us a very good foundation for the future but we'll want to add to it in the future (Lars's own todo list from when he worked at aD being a good place to start).
I've not played much with ticket tracker. I think the UI's pretty unfriendly, but that's because it just plugs into the vanilla workflow task action UI page. It could probably be made nicer with custom panels. One of the things on my wish-list for workflow is to make the vanilla workflow task action UI page configurable by the application.
