Dont expect ARM CPU`s or even AMD CPUs to come near Intel performance, but that is easy once you have gross market share to invest in R&D.
.
On multi-threaded wintel apps, 8 core AMD Bulldozer is around i5 to i7 Sandybridge.
For single thread apps, AMD doubled X86 decoder resources for AMD Steamroller CPU core.
To me, CPU that can run HTML5 broswer, 720 dpi video and other daily productivity apps and good OS is enough for 90% of people.
And Cell offers MORE PROGRAMMIBILITY then those high performant CPUs that can just share thread overload with bloated software (Win) that doesnt even use it properly.
To bad PS3's SPE's IEEE 754 support is gimped.
For GPU command generation, DX11 can use multi-core CPUs.
With 128GB SSD drive and Windows 8 Pro RTM, my Acer Iconia W500 tablet (AMD C-50 APU) operates smooth and quick e.g. MS Word 2010 loads about 1 second.