This is one nice side effect from the changes in the PC and server landscape. I haven't seen this much innovation out of server, desktop, and laptop architectures in a long time. Not only is HP moving to ARM, but they are also talking about memory architecture changes and other changes that have been sitting on a shelf for a while now. I see it as being caused by a shakeup due to threats to longstanding business models, and I think that it is a good thing in the long run.
Hp it is not moving to ARM, Hp is doing only a full range strategy. It will be the customer that will decide what to buy. The cloud market is interesting, not the more lucrative around for a manufacturer but interesting. Obviously the main HP goal is to sell expensive and powerful Xeon based servers, all this effort on cloud and microservers is to stay in a game that will account 10/15% of the next years server market.
Enterprise server market is going through interesting phase. Servers market fragmentation is getting blurred. No more companies are looking for expensive and unflexible servers but cloud based services due to improved security and connectivity. If server farms are to be maintained by large companies then server chips need to be energy efficient.