To clarify, we own all of our own hardware and the currently-deployed hardware is not yet obsolete (E3 machines can run all current games with ease, at any size), so we won't be replacing our fleet of machines. We will be using these new E5 processors for new machines that we roll out, once the processors and accompanying hardware can be reliably purchased.
The new E5-2690 processors are faster than old 2P offerings, it appears, but by how much is still not clear. All of the benchmarks that I have seen so far focus on overall machine performance with many concurrent threads involved, and they show improved performance over the older X56xx processors partially just because the E5-2690s have more total cores. Many also do not consider the fastest Westmere processor, the X5690, a 3.46ghz part. When it comes to game servers, we care mostly about raw single-threaded performance, with secondary concerns of performance/cost and performance/watt. It's most likely that the new 2.9ghz E5-2690 processors are something like 5-10% faster than old 3.46ghz X5690 ones on a per-core basis, which isn't terribly remarkable; but, the power savings are, giving them a pretty amazing performance/watt. Performance/cost is about the same.
On the 1P front, compared to the E3-1270s that we currently use, I don't think that the 6-core E5-1650s/E5-1660 processors will be faster on a per-core basis. But, we will likely still offer dedicated servers using these in order to give customers who need to run additional servers a beefier option from a total-processing-power perspective. There's a fairly large gap between the E3-1270 and dual E5-2690s.
Thanks for clarifying this.