Altera finally wakes up. They realize that the window register type architecture is not good for FPGAs and probably in general. They can no longer support their own marketing hype about how great Nios I is. If Nios 1 was so great, why did it need a complete redesign and rearchitecture? It means it was poor. That's the only reason you do a complete redesign. I believe they have switched to 32 bit instructions also. Didn't it used to be 16 bit? Guess that wasn't so great either.
They copy the Xilinx Microblaze style implementation. To me it shows who knows what about designing and running a soft processor in an FPGA. Enough said.
They throw all the current Nios customers under the bus. Requires publishing a 38 page app note to switch a Nios 1 to Nios II design. Current Nios users, I feel sorry for you. Be careful and do your back ups!