Actually, I would think that this would be of use to programs that were CPU intensive (graphics, calulations, etc.) on mobile devices since the CPU on them is slow to begin with.
For example, in Atomichelix PGP for BlackBerry
it's very computationally intensive during keypair generation. An RSA-1024 takes about two minutes to complete, of which we've narrowed it down to the fact that BigInteger's method "modPow" is not written natively in the BB JVM, so it's slow. We have yet to get our hands on a Bold to test the new CPU, but just from stats it looks like it's about twice as fast, so even at one minute, it's pretty long. Is our application on hold because of it? No, because it's generally not done very often. Could it use a speed up? For sure.
Most software on the platform won't need the speed. The most likely candidates (I see) are games. As the screen resolution increases, so too does the need for a faster processor. At 320x240, you probably could get 30 FPS from the 8xxx series devices. If those processors were in a 1600x1280 screen, you'd be lucky to get 2 FPS. And since games need the framerate, they need the CPU to be as fast as possible (since there's no GPU in a mobile and the CPU handles everything).