I'm afraid this cannot be done - as was alluded to in the previous posts. The iPad's operating system, iOS, does not allow one app to 'control' another and interaction between apps is very limited and is totally under the control of iOS. It's not a hardware issue that any new iPad could address - it's entirely a software issue and Apple have shown no inclination to go down an alternate path. Indeed to do so would require such a fundamental rethink of the philosophy of iOS that it seems inconceivable that they would contemplate it. So the only hope is that any such functionality would be built in to the basic iOS itself. We have already seen the next generation iOS - iOS5 - and it's clear that it's not built into that. Given that we're likely to be using that version of the operating system for the next couple of years, I very much doubt that we'll see any move towards what you're looking for in the foreseeable future.
Tim