Jus wondering, but what levels did you anticipate before the old forums crashed, that are gone now? Personally I was looking forward to The Obelsik...
The Obelisk, you mean. (By JerkDouglas.) That level had lots of promise. Also, Resolution by Si, especially because it has two other excellent levels setting it up. And Etherworld III by Noi, which also had two other excellent levels preceding it. (A portion of Etherworld III was released as a beta, but withdrawn after Nifflas voiced his disapproval of the usage of pip's NG tilesets.)
These levels aren't necessarily dead, of course. It's just that anyone who starts a large project is bound to lose interest at some point, at least for a little while. JerkDouglas, Si, and Noi hadn't been particularly active on the old forum.
However, I can think of two instances where a level maker returned to finish a major level; Farik came back and finished Harvest, and Johnny Chthonic came back and (nearly) finished Paradise Last before drifting away again.