About ubuntu server packages

[carlopmart]

Hi all,

  I would like to migrate my centos 4 servers to ubuntu LTS 8.04 when it 
will be released to build xen robust servers using redhat cluster suite. 
But I find a problem: how can I see which package have 5 years support 
and not 3?? Why ubuntu server doesn't use separate repos like rhel does??

  I think it is a big problem for sysadmins ...

Many thanks.
-- 
CL Martinez
carlopmart {at} gmail {d0t} com