MacBook Pro 4.1 not responsive?
It's likely that the controller for the trackpad and keyboard (I believe it's one chip for both) is dead. I had an issue where the keyboard and trackpad on an older pre-unibody model would become non-responsive, but the rest of the top case components were fine (power button, back light). It was tracked to a faulty controller in the top case, but the solution was to replace the whole thing.

iFixit sells replacement top cases, but they're rather pricey ($299.95 for the A1260-compatible part). You might be able to find a cheaper one used on Ebay or elsewhere. The repair itself is fairly straightforward.

Have you tried plugging in a USB mouse or keyboard yet? If the problem is what I think it is, that should work fine.