ARM still has a long way to go to catch up to MIPS for multi-core or 64-bit. For Broadcom, they would loose at least a year if they swapped to ARM to get to the same number of cores and 64-bit as they currently have with their MIPS ISA. A real pity that MIPS was so greedy when they still had Sony and Nintendo as customers. I still recall the prices of Silicon Graphics boxes, the Compaq fiasco, it just keeps coming back in nightmares. I wasted years working with various MIPS devices.
This is chump change for Broadcom to protect its long time interests. Hopefully this keeps MIPS (company) alive for a bit longer. Broadcom will be one of the few companies remaining that continue to be a MIPS house. Remember that it paid a staggering $4B to acquire Netlogic for their MIPS processor implementation. They don't have an option but to continue down the MIPS line.