I am a big fan of virtualisation, the main reasons for me are:
Agility (ease of scale out, provisioning, server management, deployment, etc)
IMO virtualisation is the default stance, give me a reason to not virtualise!
Here are 20 things that everyone, OK maybe not everyone, but certainly every IT Pro, should know about virtualisation:
Both are lightweight articles that will only take a few minutes to read through ;)