Dude! The last release of Project Forecast was in July? High time we get another one.
This release candidate features compatibility with the current Views and CCK releases (at the moment, that's Views 6.x-2.1 and CCK 6.x-2.0-rc10) so if you needed to defer updates because of Project Forecast, you can now update to these newer versions. (As we all know, Views 6.x-2.0-rc2 brought a pretty grave incompatible change so all the modules had to adapt their Views integration.)
Oops, just noticed that the Milestones extension module didn't get updated to the new Views yet. You'll need to wait for another release for that :P
Also, this release candidate features further usability improvements, most importantly the combination of the general ("Relationships") and "Task filters" configuration tabs into a single admin settings page.
And lastly, this release also contains a new add-on module, Project Forecast Task Status, which makes it possible to influence a task's time need (for the calculation, at least) depending on a task status field with fields like "open", "in progress" and "closed".