Microsoft create the smartphone market as well. The iPaq was the model Apple used for the iPhone. I don't think Microsoft will be competitive in that market either.
Google will dominate both tablets and phones - they already dominate the phones.
It doesn't matter. If you use your Android-powered Samsung phone to access data using Microsoft technologies on Microsoft servers than Google really hasn't accomplished anything. When MS wants they'll simply port their OS to the Samsung phone and you'll have "CHOICE".
(We all believe in choice, right?.... well Appleidiots don't.)
You like someone else's phone better? Then go down to the store and get yourself a new phone. Takes 15 minutes. Who cares what OS comes on it.
The organization hosting the data you access will probably put a little more thought than you do when they're considering replacing their LAMP environment with Microsoft (or vice versa).
Since practically nobody uses Apple for server, virtualization or cloud-based services you can be that their easy-come popularity will be easy-go popularity. They're consumer electronics. I don't know that Microsoft does or ever did care about that space (XBox excepted)