yes there is a few positive article for Linux/Redhat linked
from RedHat main page http://www.redhat.com/
This one is interesting because they recognise that linux
is gaining some users on the low-end Sun market (Sun4c Sun4m).
They of course insist on the fact that it is not suitable for
high end machines (the real purpose of the article, IMHO), while
they perfectly know that UltraLinux is the first real 64 bits
os for the Ultras and that it runs on the Enterprise line of
machine (except the very high end if I understood well).