To add on to what Rob posted, Universal owns about 2,000 acres on the Lockheed land, give or take a few hundred since some of it was sold to the state for use with the new convention center (some more of it may be used if the proposed bullet train is built).
The extremely long term (and I can't over emphasize LONG TERM. Some of this may turn out to be wishful thinking) master plan for Universal calls for 4 theme parks, numerous resorts (potentially as many as on Disney property), another water park, another shopping and dining district, timeshare units, golf courses- the whole nine yards. I should add that all of this is still fluid and we are probably 8 to 10 years away before something is really done with this land.
In the more immediate time frame, plans call for two more resorts on the 840 acres that currently houses Universal Orlando. One of these is supposedly going to be very large (5,000 rooms is the current rumor going around). Don't be too surprised if an announcement is made this year about a 4th resort at Universal.
I've got to agree with Rob though, the Hard Rock Hotel is the best resort on property, with the Portofino being a close 2nd.