One awesome thing about this is a lot of the time when the web frontend to Gmail is down, POP3/IMAP remain accessible - so vmail would be a great drop in there. (As would a myriad of other MUAs). As a vim zealot myself, I salute you for this commendable idea.
I just posted the link -- I didn't write the plugin. :)
On the topic of Gmail downtime: Vmail's method (use IMAP) isn't quite as robust as, say, Mutt + offlineimap, but it's a hell of a lot easier to configure.
