Tonight I tried to import some plug-ins but received "Internal server error 500". I found a related OTN forum post with a recent comment saying it's solved in 2.0.1 - I'm pretty sure I didn't have that version.
So I just downloaded the latest APEX Listener and had immediate (successful) results.
Since I run the listener stand-alone, so all I did was unpacked the file to C:\apex_listener2.0.1, changed my "start apex listener.bat" to
java -jar apex.war standalone --apex-images \apex4.2\images
and restarted my listener. I didn't even have to log back into APEX ;-)
For those listening (no pun intended) on twitter, follow @krisrice for relevant announcements.