Some of us started discussing this in the Christian org thread, but since there's a (very interesting!) theological debate going on over there... I didn't want to hijack the thread any further.
At my school, in my day, there was something of a split between Hillel and the greek community. Orthodox Jewish men tended not to go greek. Conservative and Reform men often did look into greek life; some kept their options open while others only considered AEPi (which is the only fraternity we had whose membership was predominantly Jewish). Orthodox women were more likely to consider greek life - I had three Orthodox pledge sisters.
The problem lay in the fact that the Orthodox men pretty much ran Hillel. Some Orthodox Jews consider members of the other movements to not truly be Jewish

and this was the prevailing attitude among the Orthodox at my school. "We have a problem with non-Orthodox Jews" + "A lot of non-Orthodox Jews are greek" => "We have a problem with the greek community."
Some greek orgs, notably AEPi and AEPhi, did things oriented toward the Jewish community (a break-fast after Yom Kippur, Tay-Sachs testing, etc) and Hillel did promote these things, but I think only reluctantly... the Orthodox wouldn't go.
From people I know who are still in that community, though, I gather that things have changed and Hillel is making efforts to reach out to greeks.