Gakai is a bit special, you can't just fit that into their standard servers.
This is true. Does it make sense then, given that Sony's committed to creating their own data centers anyway, to bifurcate their server deployment between their own servers and those of third parties? Wouldn't it make more sense to create their own mixed data centers for Gaikai/PSN and benefit from being able to consolidate network resources, administration costs, etc.?