More than iOS and Android SDKs?
There are 1.5 billion PCs world wide.
Are all of them running .NET?
Gee, when have we heard this before. Oh, yes: when the iPhone was released.
This is why these "mobility" servers like IBM WorkLight or SAP/Sybase Unwired are hot products.
Blackberry's are going away, we have remote email via iOS, and its only a matter of time before other people get the gear sales has.