Hi Will,
You will have seen from the release tracker what state the module is in, and that it has finished the testing phase. A number of issues were highlighted, which are all marked in the tracker. However, as far as I am aware none of these are showstoppers for 4.0.1.
Some of the issues highlighted, the team has worked up fixes for. These are shown on Gemini, and are marked for a 4.0.2 release. Some other items are marked for 4.1.0 release, the biggest piece of work being XHTML compliance.
Note that a 4.0.2 release is not confirmed yet, but I would expect there to be a bug fix release prior to the next major release, since these small bugs have been found and can be fixed easily.
I am not aware of any delay for a DNN 5.0 launch.
In effect, you know pretty much as much as the team does. Gemini is kept very up to date, as to what the team is working on.
Cheers
Roger