Why is the kernel still at version 2.x after upgrading from Ubuntu 11.04 to 11.10? I read that 11.10 has 3.x.
Yes 11.10 have version 3. Just open synaptic (I still use it) and mark version linux-image-2xx for removal and 3xx for installation. Also install the headers for 3xx as in future you might need to compile something that needs it.