I'm waiting for one to do a review, but am not expecting anything where images can be shown, until pretty close to release. I've got one on its way at that time for me too, just in case Canon(UK) don't have any suitable review cameras for a while (this has happened in the past with several releases)
In particular I'll be doing direct side by side comparisons with a 1Ds3 and hope to make some of the raw files available for others to draw their own conclusions.
As well as straight one to one comparisons i was also going to start having a look at the multiple exposure options to see whether either from a practical or quality point of view, they are a useful addition (for my own use)
When we get closer to a release, I'll be asking people to send me requests for comparisons, and I'll try and fit a lot together - hopefully making the comparisons a bit more useful (just don't ask for video or AF testing ;-)