IBM x86-64 PowerPC CPU?

No.

It does not fit into IBM's business model which is basically focus on servers and more importantly integrated and proprietary software solutions for businesses to manipulate and manage data.

They do manufacture the Cell CPU for PlayStation, the CPU used in the Wii console, and derivatives of the PowerPC CPU for their servers. However, facing off against AMD and Intel for a piece of the x86-64 pie.

Can they enter the "home CPU" arena? Sure, but it really does not fit into their overall business outside of their minor business with game consoles. They already tried and failed with the PowerPC CPU, it only entered the "mainstream" market because they were used in Apple's Mac PCs and laptops until Apple decided to use Intel CPUs some time back in 2006 I think.
 


IBM could. IBM has chip modern chip fabs and an Intel x86 license. They used to make x86 CPUs using Intel's designs up until around the time the Pentium MMX came out, then they went to making PowerPC-based CPUs since they thought that would overtake x86. However, they won't because they are out of the PC business (sold it off to Lenovo a few years back) and are very content to sit back and sell big-iron POWER and zSeries servers and the hugely-expensive support contracts that go with them.



The PowerPC was a victim of IBM's previous success. They introduced the IBM PC with an Intel 8088 CPU, it sold like mad, and basically set x86 as the home computer ISA. IBM was apparently toying with going with the Motorola MC68000 (m68k) instead of the 8088 but for some reason decided to go with the 8088. If IBM had gone with the m68k, we would probably be running PowerPC CPUs today since the PowerPC can run m68k programs reasonably well and would have allowed for people to use newer CPUs with legacy programs. That same reason is why we're running x86_64 CPUs today instead of IA64 Itaniums, despite Intel trying their hardest to push Itanium as the replacement for x86. x86_64 allowed for a clear and easy way to continue to run old x86 applications, while IA64 didn't. (Actually, the Itanium did do x86 emulation, but it was terrible, and Intel has since removed it in current Itaniums.)



I doubt IBM would want to buy AMD. What AMD does doesn't really fit in well with IBM's business strategy. The only company that I could see really wanting to buy AMD would be somebody like Apple or maybe Google. Apple is in love with vertically integration and having a CPU, GPU, and core logic company with a big share in a fab would be heaven for them. They would be able to specify CPUs, GPUs, and chipsets that exactly fit what they wanted to do with their products, and they could make them as proprietary and incompatible with other parts as they wanted to, as long as the chips can run x86/x86_64 Windows applications in a VM. That sounds exactly up Lord Steve's alley, judging by what he's done and said in the past.