Not possible with the current state of the SDK, that's not to say that it's completely impossible (it certainly isn't) but it requires quite a bit of development. You need to load (and link) the application manually into memory (at the correct address) which would overwrite the current program. So to preserve the current program you'd need to move the current program onto the heap, also you'd have to modify the memory system in the SDK.
It's possible, but a lot of work to implement, unfortunately the operating system is very minimal and under-featured which means that the SDK is responsible for a lot of stuff that it shouldn't really need to be doing.
