I'm sure it's a drop in the bucket compared to merchandising, and it's been pretty well documented that merchandising is Lucas' main goal. That's not a "hater" mentality, it's a fact - it's been that way since the days of Return of the Jedi (Richard Marquand, were he alive, would be the first to point out the creative hits that film took due to merchandising).
The films combined have made a couple billion dollars. The merchandising has made more than 20 billion.
I think the reason it hasn't been a priority is what I previously stated - they already make so much off of the merch and the increasingly "merchandise events" known as Star Wars Weekends (put some people in costume walking around, and get a few C and D list Star Wars performers to sign some autographs, suddenly it's a month-long event). They could invest a half a billion in a Star Wars land, but it probably wouldn't sell them significantly more merch than they already do as they squeeze it so dry it's a miracle they haven't started stocking Star Wars toilet paper yet.
I still dream it - Lucasland, or Muppetland, at the Studios. Either one would be a dream come true.