The goal of Rambus TM is to solve the memory bandwidth problem. In order to be successful, a new technology needs a roadmap for adoption. Thus often the successful ideas are the least risk ones.
Cost is a major issue.
Don't compete in the DRAM business. Instead, find some sort of related niche. For example, a field reconfigurable memory chip. The feature size is decreasing by 0.7 every 3-4 years. The typical power consumption in a DRAM is 0.5 watts.