Agree with Conor on this to a great extent. It was a bold idea, and they deserve props for trying it out. They had to do something with ARM, whether they could've come up with something different is a question which will never be answered.
And as Intel becomes more competitive with ARM on power consumption they shouldn't have to delve into ARM waters again, though I don't think Haswell is going to be quite as competitive as Intel thinks, so it won't be just yet. All that said, if they can make Winmo phones using the same chips as PCs they'll have an enormous edge over Apple with Intel for MacOS & ARM for iOS. Android can only run on ARM, though OS Chrome is only Intel, the apps are browser based so therefore agnostic. Interesting and risky times for the tech giants...