Right now the research paper is on the front page, but if it isn't there, it is research note F33. They also have papers on the Real ROI from Oracle E-Business Suite Applications (E36) and the Real ROI from SAP (D23).
Nucleus Research Finds 82 Percent of PeopleSoft Customers Achieve Positive ROI on Average of 2.7 Years
UPDATE: After reading the actual reports, I am much less impressed with their 'research'. The paper reports that they identified and contacted 105 PeopleSoft customers. Of those customers, only 17 agree to participate. I'm no statistician, but even if we pretend that 105 was the total population of PeopleSoft customers, we are still talking about something like a 20% margin of error. When you consider that the actual number of PeopleSoft customers is considerably higher than 105, that margin of error is going to become even wider. With a margin of error like this, what does the statement that "76% of PeopleSoft deployments were completed on time, and 47 were completed on or under budget"? Seeing that this is somewhat of a self-selected group, I wouldn't be surprised if these numbers were on the high side of that margin of error.