Nah, it's just patent trolling. They wait until their patents are widely used, even when they know that a company is about to use a tech covered by their patents and only when it's widely used (aka when the company has a lot to lose) they sue the hell out of them.
And they didn't even develop most of the tech that their patents cover. I think that 90% of their patents were adquired when they bought some small companies. Like this from the OP:
1. Rambus is the exclusive licensee for the Dally family of patents which are owned by Massachusetts Institute of Technology. This license was assigned to Rambus as a part of its 2003 acquisition of technology and IP from Velio Communications, a company founded by Dr. William Dally.
I mean how stupid can that be? Rambus is suing Nvidia because Nvidia is arguably using some patents that Rambus has licensed from another comany who adquired them from William Dally, the current chief scientist and vicepresident at Nvidia.
The patent system is just broken when such things can happen IMO. Intelectual property should only belong to it's creator, and should not be able to change hand's because the concept of intelectual property was created with the purpose of protecting the creators from other people duplicating their work.
I also think that IP should never be owned by companies to begin with, because the future of most companies (and their owned IP) does not belong to the creator (of the company or the tech, doesn't matter), it's completely on the hands of investors. This way the inventor of a new tech who creates and invents IP for a company in the name of stability and advancement in that company can see his IP sold without being able to do anything. How is that protecting intelectual property? Intelectual property of who? A company is nothing tangible, it's nobody, just an abstract concept and employees that come and go, so who's IP are patents protecting in this day and age?