Ok started running around testing various level 65 hunting spots at 70.
PoN:
The gnarled treants and other mobs were light blue. Got ~1-2% AA per kill. Then I ran across to hedge. The banshees were light blue and gave about the same exp. The nettling wraiths were all DB and gave 2% per kill. I then ran past the guardians and tried out the gargs. They were all DB of course, but still only gave 2% per kill.
PoI:
Lot of light blues. Didn't have much time, so didn't get to test very much. Mobs gave ~1% per kill when light blue. I checked the factory and the tin soliders were light blue as well and gave ~1% per kill. I didn't pull the other DB mobs inside so not sure what they'll give for exp.
Sample size for all of this is smaller than I'd like, but I have so many different things I'm testing atm I'm just trying to what information I have out there now and hopefully others will add on even more. I plan to test tier 1 a bit more and then hit other spots like droga/griegs/etc. Not sure when I'll have time for that though. *shrugs*
One thing I've wondered, is there an exp penalty for light blues. At 65, gnarled treants and co in PoN would give me 1-2% aa. So if they still do it might indicate no change.
I believe light blues are have a 50% exp penalty, but I don't recall atm and can't check on that. The exp is down on light blues from what I can tell by the differances between the light blue banshees and the DB nettlings wraths that I don't believe I really noticed a diff in exp on before. I'd have to dig back through some old notes to be sure though.