Specifically The Wisconsin Alumni Research Foundation or WARF is involved in the suit.
Here is an excerpt from WARF's site:
WARF filed this complaint to ensure that the interests of the UW-Madison and its inventors are protected and that WARF receives the compensation to which it is entitled for Intel's unlicensed use of the invention. This compensation will be used to advance continued research at the university. The foundation's complaint identifies the Intel CoreTM 2 Duo microarchitecture as infringing WARF's United States Patent No. 5,781,752, entitled "Table Based Data Speculation Circuit for Parallel Processing Computer."
The technology, patented in 1998, was developed by four researchers at the UW-Madison, including Professor Gurindar Sohi, currently the chair of the university's Computer Science Department. Intel has aggressively marketed the benefits of this invention as a feature of its Core 2 technology. "The technology significantly enhances opportunities for instruction level parallelism in modern processors, thereby increasing their execution speed," states Michael Falk, WARF general counsel.
The WARF patent discloses and claims a data speculation circuit that facilitates the advanced execution of instructions before other instructions on which they may be data dependent, resulting in improved execution efficiency and speed. "The technology of the UW-Madison researchers has been widely recognized in the field of computer architecture as a pioneering invention," states Falk.
According to Falk, WARF contacted Intel in 2001, and made repeated attempts, including meeting face-to-face with company representatives, to offer legal licensing opportunities for the technology.
"We are disappointed with Intel's lack of response in resolving this matter, and while we were not anxious to use the courts to enforce our patent rights, we have no other recourse given our duty to protect the intellectual property of our inventors and the university."
Details from engadget and the University of Wisconsin.