Northlight Images have posted specs of a 1D Mark IV that is currently being used by a Canon Tester:
- 1.3 crop
- Images ~16MP
- ISO 50-25600
- 8MP sRAW1 format providing images that seem to best 1D3 files in detail
- Very clean images at ISO 3200. 6400/12800 take further processing very well
- Slightly faster FPS than 1D3 in real life shooting
- AF greatly improved and very good in low light (actual comment was 'Nikon fast')
- Liveview AF - not up to fast sports use, but very usable otherwise
- Video as with 5D2
- Screen as per 5D2
- Ergonomic improvements with grips - some buttons moved
- Feels faster and more responsive in nearly all aspects of real use.
They also add that this may not be the final form of the camera. Source: NI on 7/1/2009. | 
, B&H Photo Video, OneCall, Adorama 
