I suspect 5D3 will have an AA filter, hopefully not too strong of one.
However, one bit of info I read last nite that gives me some cause for optimism is the latest version of DPP software, shipping with the 5D3 and soon available for download I suppose. It includes something called DLO which sounds like it's going to improve image sharpness, CA, etc., better than past versions of DPP. This is supposed to be effective on all EOS bodies back to 2006.. G-series too I hope.
This software upgrade could improve my tens of thousands of existing images!
Current version of DPP I already find gives DxO more than a run for the money when it comes to sharpness and detail in highly complex scenes with lots of very fine color detail, like autumn foliage landscapes. DLO feature could take it up another notch and relegate my copy of DxO to fewer shots where I need some critical feature only it can perform.
According to Jeff Ascough, the AA filter is thinner: «Canon have made the anti-aliasing filter thinner to get higher quality - BUT - if you decide to put cheap lenses on this camera you may find them wanting.»
I guess we have been offered some foresight into the future preferred methods. Thinner AA filters and I'd software to correct. I'm wondering if the thin AA filter is available because of the gap-less lens design on the sensor.