As a shooter, and as a teacher,and as a tech blogger, I need the most recent equipment. So I have no obtained a Canon 1D MkIV to replace my 1D MkIII.
So far it seems fine. Not the same great focus system as the 7D, but th same solid feel as the 1D MKIII and the same software options, which Canon has left off the 7D (e.g. the option to name the files to your liking). And lowernoise than the 7D (of course, if only because it is a 1.3 crop factor sensor). Fast 10 fps shooting that lasts much longer than on the 1D MkIII. Sozen of full RAW shots before the buffer fill sup even with a slow memory card.
So far. so good. You can be sure I will post detailed information, rather than these very first impressions, in the next days.