FYI to all:
I'm cautious about upgrading to new versions of WP and wait a while, mainly to determine if any plugins are incompatible. Also, W3TC isn't officially compatible with 3.1.1 yet.
However, I just upgraded to 3.1.1 and the following plugins are fine for me with W3TC.
After the Deadline
All in One SEO Pack
FD Feedburner Plugin