WotC has put up their release schedule through April 2012. Looks like Heroes of the Elemental Chaos is the only actual book being released in that period for 4E. Hmmmmm. I'm sure the two tile sets and the boardgame that they are releasing make the product schedule look full from WotC's side of things...but....sigh.
This is why I like Paizo. Those guys know how to crank out books, and it seems to me that they know that not all gamers will buy all books, but variety is the spice of life, and inevitably Paizo will release a Pathfinder sourcebook or module that will snag someone's money, somewhere. I really have no idea if this is how it's actually done, but it seems to me that releasing 5 products with, say, a 20,000 print run and the expectation that each product will appeal to a different gamer (and a few collecting all of it) is a better approach than putting all the money behind one product with 100,000 copies, and hoping that all gamers everywhere will buy it simply because they are starved for content.*
*On the plus side, if someone were trying to find a game line that was less expensive, WotC's got that part covered. With their rate of releases these days I'm looking at only three book purchases for 4E over the course of the next 7 months; I'll probably buy at least 1-3 Pathfinder books every month in that same time period!