Rambus does release memory technologies, like XDR. Don't forget, RDRAM killed DDR for the Pentium 4 when it was out. They have, and do still make products that can be useful.
But, if I were the CEO of Rambus, I'd branch out and not only offer memory technologies, but legal services. They've got enough experience at it, and a pretty good track record.
Putting chumps like NVIDIA in there with Rambus is like putting a goldfish in with a piranha. NVIDIA is good with the bluster, but they are completely overmatched going up against Rambus legally. Hell, outside of Microsoft and maybe Intel, everyone is.