Ok, the Pydev 1.4.2 is just out.
The major feature this release has been long awaited: each project can now have a different configured interpreter.
As a result of that change, some internal structures will have to be recreated. So, right after upgrading it's expected that Pydev will do some processing to make that right, and now, it has to gather the information for all the interpreters, and not only for the current one, so, be a bit patient while it does that (it'll do that just once).
Also, many fixes were made available, so, upgrading is really reccommended.