Not something easily reproducible so that I can profile the IDE. I've generated three thread dumps with an interval of 30s between them. Let it run for 10 min before giving up.
Product Version = NetBeans IDE Dev (Build jdk8lambda-1641-on-20130208)
Operating System = Windows 7 version 6.1 running on amd64
Java; VM; Vendor = 1.8.0-ea
Runtime = OpenJDK 64-Bit Server VM 25.0-b15
Created attachment 131155 [details]
Created attachment 131156 [details]
Created attachment 131157 [details]
Created attachment 131158 [details]
Created attachment 131159 [details]
I am sorry but running that build on JDK8 was a bit premature. Please try using some 7.4 dev build or 7.4 beta when it is out on a very recent build of JDK8. Closing this report as wontfix.
Looking at the thread dumps: it seems like there should have been some dialog showing and the AWT thread was just waiting for the events from that dialog. Not sure what dialog was it supposed to be and also why you were not able to see it. But as I said this was too soon to try to launch NB on JDK 8....