Hmm
I personally love Redhat, or rather the OSS flavor CentOS, that is why it powers 90% of my server.. but I think your smoking something if you believe this is biting into vSphere. Its not even close.
Commercial Linux and Java development tool distributor Red Hat has big aspirations in the server virtualization and cloud computing arenas, and it looks like the company is getting ready to bust out the 3.0 version of its Red Hat Enterprise Virtualization hypervisor – RHEV for short. Red Hat has cooked up an all-day event for …
....what? VMware and Microsoft?
You must be smoking something highly illegal there, pal.
On the other hand RHEL is ridiculously overpriced and their pre-sales support downright sucks, with their regular support being mediocre.
As it is today I'd take XenServer 6 any day over RHEV, sorry.