Anything is possible, but upgrading an ePods with this CPU would entail esentially redesigning the processor board almost from scratch. Possible yes, practical no, expensive extremely.
Even though the processor you reference is MIPS based, that only covers the CPU core. The toshiba part contains more than the mips core but other peripheral logic such as the Bus Interface, real time clock, serial interfaces to name some. The chip you reference may indeed also have some of these functions but there little to no chance that they would be implemented in the same way Toshiba did there.
Next, even though they both may have a MIPS core the physical packages would not be the same. There is no set processor socket like the intel Socket 7. Each manufacturer assigns the pinout based on the IOs of their particular processor and the physical layout of the chip. Power and grounds are assigned based on the physical package used and the physical chip design.
So even if by some incredible long shot chance that the processor you reference came in a package with the same number of pins using the same pitch and grid, the signals, power, and grounds would never line up for every single pin.
Lastly, if the processor you reference is running at 450Mhz+ it will have a lower core voltage than the Toshiba part. It will also require a different reference clock. The epods board is designed for the processor it has not others.
In reviewing the list of things that would have to be compatable between the processors, I cannot find one that would be compatible. As I said at the beginning, anything is possible and you could essentially redesign the ePods board to accomodate the new processor but it would be less expensive to design a new system from scratch than trying to work around all of the incompatabilities.
I have only pointed out the blatantly obvious and if these did not occur to you then you have no business trying to upgrade your hardware. No offense intended, but you would be in way over your head attempting any HW upgrade to the ePods unless you educate yourself on some of the fundamentals.