I would like to see from Telerik a framework for developing for the iPhone like one of your competitors does. The iPhone is gaining big momentum. There are over 15,000 apps for it in a short time.
You might be waiting quite a while for anyone to be doing this... Telerik works with the .Net framework, which is Microsoft's baby. iPhone programming is done using Objective-C/Cocoa, which you could call the .Net of the Mac world, except (in my opinion) it is not nearly as robust or user friendly. Admittedly, I don't come from a C background and I know that helps people with getting into iPhone programming, but in working with a few books I'd still choose .Net over Objective-C any day of the week.
One option for you if you're looking to make games for the iPhone is the Unity3D framework, which is a bit pricey but lets you use a Windows machine to program for the iPhone, but only game development (so you wouldn't even be able to use your trust Telerik Winforms or WPF controls with it!).
Plus, everything is run from the rather closed and proprietary XCode dev environment, which is pretty locked down to only using things made by Apple (as they are known to do, just a bit!), so getting third party controls into that environment would be tricky if not impossible.