Information can be found in /proc/version.
A process exist for installing kernel modules. You can download the archive on http://mirrors.gandi.net/kernel/ , uncompress it and copy the directory to /lib/modules.
Activation of CONFIG_IP_ROUTE_FWMARK. Fix for CVE-2009-3002, CVE-2009-2848, CVE-2009-1895, CVE-2009-1337
Fix for blkfront. In some case, detaching a disk from a server was failing.
Fix for CVE-2009-2698 : udp_sendmsg() vulnerability
Fix for CVE-2009-2692 : Linux NULL pointer dereference due to incorrect proto_ops initializations