I am not surprised about this
When PA Semi was started it embarked on a product that was entirely geared towards Apple and their low power dual core PPC G5 clone was certainly better than anything Motorola or IBM ever had to offer Apple for the notebook. Yet, as we all know, Apple switched to Intel's x86 instead. Some of us were surprised by that as the PA Semi G5 alternative presumably would have had an easier migration path.
One thing Apple lost when switching to Intel was leverage. They had leverage against Motorola with IBM and they had leverage against IBM with Intel. But once they went Intel there was no more leverage. Sure, there is AMD in theory, but I don't think Intel would take Apple serious if they said "we can always buy from AMD if you don't do this or that".
Since Apple have a complete set of development tools for OSX and applications which target both PPC and x86, in theory, they could just move back to PPC as long as they keep the software PPC ready (at least in their lab). But they pretty much burned bridges with both Motorola and IBM. If there was another PPC chip maker with a competitive product, that would give Apple back the leverage they lost.
For this reason I have long believed that Apple was watching PA Semi and if push came to shove, they would throw PA Semi a bone just to keep them in business. I imagined that they might run their Airport base stations and Apple TVs or other such non-core products on PA Semi chips, just so PA Semi won't disappear for lack of customers.
Well, buying PA Semi outright is another way of keeping them alive. To my mind, as long as PA Semi doesn't lose money and have enough for R&D to keep those low power chips competitive, even if only in the lab, then Apple will win even if they never use any of those chips.
In other words, Apple just acquired the leverage they lost when they went with Intel. Smart move.
That isn't to say that some Apple product will not eventually use PA Semi chips. It's likely that they will use the chips for something, two birds with one stone, so to speak.