They play these game against BC, Harvard and UConn every season - whenever they need some competition during a break in the schedule. They used to play more against pro teams, but there were some *incidents* where guys got a little "overzealous" (one being where Giovanni Savarese's ankle was seriously injured - basically ruining him for most of the season, another where Rusty got bundled into the team bench against the MM Buck [although that was USOC, not a practice match]). I think that playing the schools on a regular basis helps build a relationship between the players on all teams involved - making it less likely that someone would do something too crazy to get noticed. Also, the college kids aren't "auditioning" for an MLS job (yet).
A little bird tells me the Harvard game is closed door at Gillette as part of the team's media day, so those of us who're usually around Cambridge and who were thinking of crashing it are out of luck.