obsolete packages ?

Hi.

Does anyone has a good understanding or documentation (even better) what is
the role of the obsoletes list on up2date? it seems that if i have 2
packages in installed on the machine, and one obsoletes another, up2date
tells me about this in

up2date -l

The following Packages are obsoleted by newer packages:

Name-Version-Release        obsoleted by      Name-Version-Release
----------------------------------------------------------------------------
---
XFree86-SVGA-3.3.6-44                   XFree86-compat-modules-3.3.6-44

but how to continue ? should i uninstall the left package ? will up2date
uninstall it sometime ?

RHN doesn't seem to have answers to these questions - and it doesn't work
well anyway in the last few days - i am getting "technical difficulties,
please come back later " messages from the site and rhn servers from time to
time ...

Does this also mean that the server will never return the obsolete packages
wher dependency resolution is requested ?

what to eat it with (i am not sure this is the correct english expression,
but anyway) ?

Thank you.