Serial NOR is definitely growing and over time will take over a chunk of the parallel NOR market as the simplified interface enables a cheaper memory subsystem. As higher densities become available and speeds increase you'll see more defection to Serial solutions. FPGA's are definitely making the move.
With only two real players in NOR it would be hard for one to disappear. While NOR isn't as big as the NAND market it is far from being "niche". Spansion's tech is being licensed too for NAND by Elpida. Will be interesting to see how that develops.
It is great to see Spansion doing so well. I wasn't sure they would make it. They appear to be firing on all cylinders. The US has two great memory companies in Spansion and Micron. Support the USA. :-)