Awesome. The digital imaging space keeps moving so fast due to the heated competition between Canon and Nikon. I upgraded to a 7D from my old 40D this year and it feels like there are way more than two years' worth of improvements in there.
These two companies seem to trade-off on features every other generation (tic-toc). I think they had a common history, some decades back.
"Their friendly rivalry" speaks to this, in a way. http://search.japantimes.co.jp/cgi-bin/nb20071226a7.html
If a 5DmkIII arrives early next year then both the full-frame series for each company will be updated.
1dx seems pretty evolutionary, it is likely that the D4 will also be similar.