First off, apologies for my first post being a new thread - however I've just searched the forums for this topic and it hasn't been covered, and I've lurked for a while
A few days ago I worked out a couple of 'kludges' (ie, workarounds) that are fairly easy to put in place that allow Msg Plus to use Gmail fairly efficiently (although I haven't tackled email notifications as yet, cos I guess Patchou is onto that one).
From my summary:
This is a short HTML script to allow you to log in directly to the Gmail server from Messenger via the link, or a desktop shortcut, with numerous problems fixed. This workaround is useful for anyone who uses Gmail + Plus especially, but also for any other Gmail users (auto-logins are good time-savers).
Essentially it means you can still use a Gmail messenger account + Plus in the meantime before the new Plus.
You can find this worksheet
http://www.littleeyeontheworld.com/blog/gm_idx.html, on my weblog. Any problems, comments, etc - post here.. and feel free to delete this if I've incurred some proviso that I missed