First, go read Pete's summary about the going-ons in Jaunty kernel-land.
The only bit I would like to add is to install the kerneloops package. This nifty little application will scan your logs for any crashes/warnings in the kernel and report them upstream as well as to Launchpad. This helps upstream and Ubuntu developers get an idea of what bugs a vast majority of their users sees and allows them to prioritize their time.
We are working toward getting it installed by default for beta, but for those of you that upgrade and keep a tight rein on what's installed please consider installing kerneloops.
sudo apt-get install kerneloops