[CentOS] 4.2 upgrade and kernels

Just curious about kernel requirements after the upgrade. I've been
running the 2.6.9-11.106.unsupported kernel for some time. Now I see
that the base kernel is up to 2.6.9-22.EL.

Are there any plans to upgrade the unsupported kernel?
Should I be using the newer kernel after the upgrade?
Does it make any difference?

Not trying to be pushy; just looking for information.

Thanks for all the good work, and tons of it.

--
Collins Richey
      Debugging is twice as hard as writing the code ... If you write
      the code as cleverly as possible, you are, by definition, not
      smart enough to debug it.
             -Brian Kernighan