Tons =)
I've been actively modeling troop trees, weapons and architecture, but I can count the number of people who have stuck around to help on one finger. A while back I started delving into coding to try to put together some of the things that we need, but I just don't have time to do it.
Right now, we've got a quite beautiful map with locations and factions all set up. The troop trees for the Corsair rats and the Abbey mice are pretty much done, and we've got bandits on the map in the form of Highland Squirrels and cultic robed rats. Monitor lizard warriors accompany rat armies and hedgehogs fight for Redwall Abbey.
I've got a lot of hare troops ready to be implemented for Salamandastron, I've got some really old, and in my opinion inferior weasel models that could be used in a pinch.
I've got quite a few scene props done, but no scenes are complete.
We've got a half-finished intro quest.
There is just so much more to do.
Realistically, I think that it might be better to just try to quickly make a multiplayer invasion map. We've already got the models, it's mostly the coding that is missing.