Eagle-eyed Adobe watchers who have read through the list of features in the next version of After Effects have seen that it will include version 1.8 of the ProEXR plug-ins. Yes, such a thing does exist, and I'm releasing it today. The next AE may not ship for a little while, but you can grab these plug-ins now and use them in whichever version you've got, all the way back to CS3.
This is a modest release, befitting a 0.1 version upgrade. The flashiest new feature is found in After Effects, something called channel caching. The quick explanation is that an EXR with many channels will read much faster if you turn it on (go to the Interpret Footage dialog and click the More Options button). More details in this blog post.
The update is free, as always. I recommend you upgrade ASAP.