clean up after update
 

I just installed FC3 and ran up2date. Now grub shows me two versions of the kernel to choose from. It seems that the new kernel is running just fine so i wld like to remove the older version and edit grub.conf accordingly.
I suspect there will be a lot more stuff that can be removed after up2date.
Is there a comprehensive way to remove old and obsolete packages after running up2date?

Obsolete packages should be being replaced by up2date - with the exception of the kernel.
Just a word of caution - keep the old kernels around. At least 1 or 2. You never know when
some funtionality crucial to you will be broken by a new kernel. You may then have to drop back a version until a fix comes along.

As Engmar stated, it's a good idea to keep an extra kernel around in case you need it in an 'emergency' boot. However, to answer your question; do this from console as root;

pick the older named kernel then;

Replacing the X's with the actual kernel package name that you'd like removed.