I think that's a great idea. I've drafted a message at http://meta.wikimedia.org/wiki/Talk:Wikimedia_UK_v2.0#Message_encouraging_pe...,
Please feel free to amend.
I suggest we go and subst it onto the userpage of everyone who's signed up - will only take a few minutes even without AWB.
Looks good. Actually, not using AWB is probably better - a lot of people have a link on their meta talk page to a talk page on their home project, AWB won't be able to follow those links, someone doing it by hand could.