I can con confirm this, happens when I press "U" to view the usage of Items in NEI.
Report:
http://pastebin.com/YQVR5HFM

Greetings
ultrasn0w

From http://ae-mod.info/Downloads/ - "For developer: Deprecates the old usage of the AEItemDefinitions via the direct method access of * blocks() * parts() * items() * materials() and thus use the new re-direct via definitions(). All definitions are now initialized, no matter what. But SubItems, Items and Blocks are not registered, if by chance are disabled. - thatsIch"

Thanks for the info!

I'm temporarily disabling AE2 integration if version rv2-beta-20 or newer is detected for now, since, while deprecated, the used API methods shouldn't crash IMHO. So I don't want to spend a ton of time of working around that if there's a chance for it to get fixed on AE2's end.

I will look into making version specific calls once the AE2 builds have stabilized (latest builds crash for me when opening a terminal, so I can't really test).

Seems to be fixed in rv2-beta-22, at least I can't reproduce it there. So I enabled integration for newer versions again.

After I grabbed the latest OC build from jenkins (1.5.4.490) and the latest AE version (rv2-beta-22), I still experience the crash whenever i look up the usage of an Item :(

Ahh, darn, I think didn't test with controllers disabled...

Got this in a dev setup (latest OC src and dev jar of AE2) and integration for AE2 doesn't get executed (potentially because mod.getMod.isAvaialable returns false).

Very latest? Works fine for me in dev with 18 and - so long as I'm careful not to crash it - 22 (i.e. getItemsInNetwork works for me, getCraftables I can't test).

1.7.10, but I probably just set it up wrong somehow. Whenever I use IntelliJ's "Minecraft Client" task, it just loads Forge and OC, none of the others. I just put the dev jar of AE2 into the run/mods folder.

It just doesn't initialize the integration when the condign option ignorePower is true. Otherwise it does (at least it initializes) work.

Ahh, that's a very good point actually, and a sneaky little bug. Using a non-power-related mod availability check now. Thanks for making me aware of that!

Your welcome. I simply set the providesPowerower option in ae2 (Mods.scala) to false and it works so far.

BTW, how do I 'publish' things in Intellij so I can stick 'em in a non-dev MC install?

Run gradlew build, then the JAR is in the /build/libs directory.