Pittsburgh used to be a "focus city" for TWA before (even though this expression hadn't been invented back then). PIT does have high yields, and, thus far, no low-fare competition. There are lots of gates available, and US uses PIT lot less han the city had expected. Unlike STL, which is too far west, PIT would allow for good north-south connections along the Eastern Seaboard (New York/Michigan/Pennsylvania - Carolinas/Georgia/Florida).
Orlando would also fit in with TWA's current strategy of chasing leisure traffic. It is already one of TWA 's biggest non-hub stations, currently connected to all three hubs, and there are also plenty of gates available. It would also be a good place to start expansion to South America.
The third possible candidate, I would like to mention for the sake of completeness, is Washington, D.C. the area around IAD is fast growing, with lots of high-tech industry, and there is a bit of a void after metrojet pulled out. Even though UAL is the dominant airline, there may still be room left for TWA to grow. Remember that UAL can only grow as quickly as the manufacturers can deliver the planes required for this growth. IAD was a focal point in TWA's network as recently as 1985, before Icahn took over the company. It seems like now, after TWA is beginning to recover from the year s of neglect by Icahn, the company seems to resume the expansion strategy from back then: In 1985 TWA had started massive expansion in the Caribbean, and they had also inaugurated nonstop service from STL to FRA (resumption of which has been slated for 2001).
On a parting note: the assertion that TWA doesn't fly 747's anymore is because of the TW800 tragedy, is bullshit. The 747 was in service for almost two years after the accident, and was phased out AFTER the retirement of the L1011. The reason why TWA doesn't fly 747s is because the older models are too expensive to operate, and the new ones are too expensive to buy. Besides TWA doesn't have the customer base to fill 747s yearround. Most airlines seem to have come to the same conclusion as TWA, as there are only two majors left in the U.S. that operate 747s.
And on the Tokyo route: TWA received approval from the D.O.T. last week to postpone the launch of this route until June 2001.