If Azure proves AMD CPU's work well in the cloud
The problem historically (I don't know if this is still the case, but I believe it is) is that the Intel Xeon chips gave better performance per-core than the AMD Opterons. Now, that wasn't a big problem on the surface because the AMD chips gave more cores for the same purchase price and power consumption, so they worked out well.
Enter per-core licensing.
For Microsoft running their own DCs, I'm pretty sure they'll cut themselves a good deal on the licensing. But for the rest of us, for Oracle users, for anyone not rolling their own or running a FOSS stack that hurts over time. And that's why Intel still rule the datacentres.