If you are thinking about building enterprise mobile apps, you should be thinking about something else first:
You are going to need a way to move data to and from devices, and you’ll need the services before you can build those apps. Start planning on those services now, leverage your existing team to build out WCF or JAX-RS APIs for the data you to need to share or accept. All that talk a few years back about SOA is now coming to fruition with an expanding new generation of consumers of web services.
Here’s another hint on that front:
JSON + REST
Unfortunately, most of that talk about SOA a few years back focused on SOAP services, and things like WS-*. Mobile devices have a constrained network pipe, so you want the smallest message possible. Sorry XML. Also, mobile devices tend to be CPU constrained, so you don’t want to do a bunch of parsing either. Sorry XML. As an added bonus, web apps are good at consuming JSON as well.
Start with services, then move on to the mobile apps.