It's a known issue – http://www.google.com/support/a/bin/static.py?page=known_issues.cs&ki_topic=15721&issue=178260&bucket=15722&hl=en&action=report – but Google really aren't giving much information on what's happening with the IMAP Migration Tool.

Such a disappointment that a company as reliable and reputable as Google aren't able to provide an approximate timeframe on return of the IMAP Migration Tool considering their heavy push for everyone to 'Go Google'.

http://www.google.ru/support/forum/p/Google+Apps/thread?tid=405c05e71d7ab6eb&hl=en

Let's get some exposure of this issue to put the pressure on Google to resolve this ASAP.

I think they updated it now: " This is a known issue affecting the IMAP Mail Migration tool. We expect a fix by March 30, 2010 12:00 PM PST."

Yeah I saw that... at least there is an indication now. :-)