Received the camera this morning. Have other work to do; limited time to test; will update here as I have time.
I printed a resolution chart on a 600-2400dpi Xerox laser printer, focused at 10x handheld with the 24-105mm kit lens, shot a single reference frame still, then recorded video at the same distance. I did this for IPB and I frame, 1080p@30 (as shipped), 24p, and 720p@60.
I renamed all the MOV files to MPG to get around a Premiere Pro 5.5.2 bug (very slow playback using QuickTime instead of native code to decompress; problem first reported 10 months ago (Nikon MOVs); Adobe may not fix until CS6; might be possible to fix with a config file change). Premiere Pro CS5.x does not have the bug, so that's another workaround.
Created a sequence and dropped in the still frame, scaled down to 1920x1080. Dropped in other clips and compared resolution chart between full res & scaled down still and video. This test was not set up to properly judge actual lines of resolution (horizontal), however the still frame is much higher resolution compared to video (changed nothing- out of the box and straight to testing). Using PPro's GPU accelerated sharpen, sharpening at 33 gets rid of excess anti-aliasing blur, and shows what resolution is actually resolved. This test might be completely flawed, but compared to the still frame sampled down, which shows 1000 lines of resolution, the sharpened 5D3 footage appears to be resolving 800-900 lines. Better than the 5D2, not as good as the higher priced alternatives. A hacked GH2 might do better in resolution only, but that's not an option for me at this time.
Comparing sharpened IBP to I: IBP has less artifacts. Will test more.
Memory cards: I ordered a couple 95MBs 32GB cards: http://www.amazon.com/gp/product/B005LF ... 00_details after reading that I-frame only needs 30+MBs or better, "the more the better". However in my quick tests the Transcend 16GB Class 6 card worked fine- no buffer warning issues, etc.
New 24-105 felt a little smoother and quieter than my 2008 model (perhaps just a lubrication issue?).
Quick summary: it will replace my 5D2; it's better than a 5D2 with a VAF filter. No other camera on the market at this price point, image quality, and features (stills and video). Quick clip of a person (camera pointed back at me), sharpened at 48 (PPro) looked pretty good (sharp enough) with noise artifacts looking like grain: combined with no aliasing, a much nicer image than the 5D2. I have another 5D3 coming in- body only, which will allow dual camera shooting: timecode will come in handy (not possible on 5D2). Anyone looking to upgrade their 5D2- it's a win. If looking for 1000+ lines of horizontal resolution and internal recording, C300 or Red. External recording FS100 or F3. Low cost hack (reliability issues, need different lenses, won't have Canon, Sony, or Red color quality): GH2. There are a few consumer camcorders that also do well in horizontal resolution: Canon HF G10, Panasonic TM900. The Canon XF10x/30x also resolve more- that may explain a few things (that's business...). To repeat- the 5D3 is a fine replacement for the 5D2: you'll have to spend a lot more to get better performance in similar low-light conditions and wide-angle lens capability (not to mention full frame DOF), etc.
More to come: resolution chart still and resolution test video.