Expansion plans at IAHChronicle had an article last weekend on the "preferred" expansion plan for Bush Intercontinental Airport over the next 20 years, if approved. There are additional details at the IAH website here. They are projecting a 70% increase in takeoffs and landings over the next 20 years, which, if applied to Continental alone, means moving from 700 flights/day to almost 1,200 flights/day. No hub in the world currently does that many. Delta in Atlanta is the largest, with 1,000 flights/day, and American at DFW is second, with 800 flights/day. Of course, both of them will grow plenty over the next 20 years too, so I doubt Continental/IAH will be largest in 2025.
The plan includes two new runways, bringing the total to seven(!). Seven runways definitely qualifies as a super-mega airport, up there with Denver and DFW. Four of them will be available for parallel approaches, meaning Continental will be able to move a lot of planes in and out very quickly, making for a more efficient hub.
The plan includes tearing down the old Marriott hotel and replacing it with new terminal space. International terminal D is also slated for expansion (probably an arm or two sticking out into the tarmac like C and E have). This seems much more prudent than one of the alternative plans under consideration, which would have demolished all the existing terminals to build an entirely new structure farther north. That seems incredibly wasteful. Obviously, they came to the same conclusion.
Airports often get a little extravagant, because, when you start talking about tens of millions of people going through your airport every year, and charging each of them a $5, 10, 15, or even $20 fee (built into the ticket price), that gives them one heck of a cash stream to build, well, pretty much anything.
As far as the local neighbors complaining, my sympathy is minimal. I know the extra noise is hard on them, but the airport has been there since 1969, and they've always said they plan to expand and reconfigure it as it grows. If you bought a house around there in the last 36 years, you had to know the risk you were taking. They should've required a signed document by all home buyers within several miles of the airport saying they understand the situation, accept the risk, and are not entitled to recourse. That would settle these protests real quick.
(Blog note: Headed to Austin for a meeting. Probably no posts for the next couple days.)