Why is it always colo vs cloud in these arguments? What about renting everything monthly from ovh, rackspace, softlayer etc? Many of them can provision dedicated servers within minutes, too.
Colocation provides a SAN in the form of calling up a datacenter storage company and having some consultants install you a SAN.
What are you going to do to get similar functionality on OVH, Rackspace, or Softlayer?