Pricing on datacenter infrastructure has decreased dramatically from what it used to be years ago. It was always a space concern in years past, but these days, space is not an issue. Hardware is cheaper, space is cheaper, bandwidth for that matter is cheaper.

We went back to using 1u rack servers, but the half rack machines rather than full size. This actually allows you to put TWO 1u machines on the same shelf if you wanted to. We don't, but the option is there if space was a concern.

Blade technology is still there, and still in use by many places, but pricing is so cheap on the "normal" equipment, and easier to replace when things go wrong, that many people have moved away from blades back to 1U systems or even regular old mini towers on baker racks like years ago.