Don't quote me on this - I've never used Accelerate and only briefly worked woth audio using QTKit. - but I would agree that if they are using Intel specific SIMD instructions then it might be easier for them just to stick to the Intel chips in their port - but then again we have the Accelerate framework in OS X, doesn't that abstract the processor specifics from any vector/intensive processing?

I think this is an incredibly daft decision on Adobe's part, the PPC products will still be around for a while and people will want their software to run reguardless of the intricacies of the platform they're using.