Office for Mac Team writes:
[...]We’ve been working with Apple from the early days of Lion, and collectively have been able to address many issues leading up to the Lion release. Many of our Office for Mac engineers have been running Lion for months, and are generally having no problems running Office 2011 on it[...]
No problems, eh? Communicator
crashes crashed once an instant message is sent and that’s basically the only thing it does. If the Office for Mac team is missing bugs this obvious, then we’re in for some treat.
At least, they already fixed it. You can grab the patch here.