found this little gem the other day from the mr list.
EXR shader for the osX guys.
Havent tried it, since I am not a mac user anymore,
but I thought some of you ( mac guys) might be interested.
So there you go.
I think its for the standalone version,
so if you need it to work inside Maya you have to tweak it a bit :)
Again, i dont know if its fully functional or not since i`m not the author
of this shader.
I hope you find it usefull.