Even though Google, Ask, Y! and Micosoft are building data centers aplenty, there won't be a glut in the market. The new bottleneck for data centers is not space. Boxes have gotten smaller and smaller - and Virtualization has added to maximizing space usage. But all of this has actually compounded the other limit: POWER.
Power is the limiting factor because each data center can only draw so much power. And as we saw in South Florida today when FP&L had to bring down to nuke plants, brownouts and blackouts. Power is the limiting factor.
"Last summer, the thought that we were headed for a datacenter glut was all the rage. It was sagely repeated by Wall Street analysts and other industry luminaries. That glut, however, has largely failed to materialize: we're as short of high-quality datacenter space as we were last summer." [t1r]