I doubt we will see a CPU change at this point.
I think Lightning connector and maybe some other small tweaks like HD Facetime camera to make it match the other current gen devices and carry it through the holiday season.
If it's thinner, lighter, has better battery life, has a new CPU and graphics, new cameras, and a new connector, then it's basically a 4th gen iPad. If that's the case then I wouldn't expect to see another update until late next summer or fall.