AxKit2 based webmail is coming along well. I now have the basic framework in place so that the backend maintains as many IMAP connections open as it needs, and will query the backend IMAP server in an entirely non-blocking manner (so other requests can proceed in parallel). I've got a basic IMAP webmail viewer working (shows folders, folder contents, and displays the email), and all works nicely with AJAX goodness (so the main page loads, then the folders load asynchronously, etc).
It's ugly as hell right now, but one of the Dahuts is helping me with that, so hopefully in the next couple of days we'll have a really nice (read-only) IMAP webmail setup. Then I'll work on mail sending, which should be fairly straightforward.
Do people still want/need a better webmail than Squirrel?