Hey Paul,
So, it looks like 3.5 is natively going to bring support for taxonomies applied to attachments.
I'm curious how your plugin will interact with that, and if you continue to continue support for your plugin.
Is there any chance you'll put any work into a migration script that converts Media Tags tags over to a native attachment taxonomy?
Note: I'm far from an expert on the 3.5 changes, so maybe it isn't as like your plugin as I'm thinking!
Any ideas? Cheers!