Hi Arick,
I think that the most complex thing about mobile testing will be environment support, and how this will be influenced even by the different flavors of the phones and o/s that you will get in each.
I've worked with a number of customers working on mobile devices, and for most of them the biggest challenge was getting a hold to enough "native devices" as possible. For this a number of them used systems like
http://www.perfectomobile.com/ if they wanted to perform their tests internally, and some of them went for the approach of "in the wild testing" that you can achieve with companies like
http://www.utest.com/.
There are also some pretty good functional testing frameworks that you can use (both for tester and dev testing) such as -
http://experitest.com/.
BTW, one of the biggest challenges will be making sense of all your tests and results, as well as managing all your test library, requirements and issues, for this one you can check out the system we are developing in our company -
http://practitest.com - as I said we have a number of customers working on mobile apps and managing their process with us.
Hope this helped!
-joel