They have started to close down Terminal E. Two of the three fingers are still open, but the south finger is now closed. Soon they will close the middle section off as well. That will leave the north side (which is the longest walk). The last I heard they may keep those gates for the 1900's, while the Dash 8's, Dorniers and SAAB's will move to Concourse A.
nothing is going in its place. PIT is shutting it down because of US Airways' decrease in flights over the past year and they say its unprofitable for the airport to keep it open. Therefore they are consolidating US Airways Express operations to other US terminals.