"The EOS 7D's specification and current pricing make it also look very good next to its most direct competitor in the enthusiast bracket of the market, the Nikon D300S. It offers a higher nominal resolution and maximum sensitivity, better movie mode specification and slightly faster continuous shooting speed than its Nikon rival; but having said that, in many ways the two cameras are not too dissimilar, and it will be down to personal taste and probably your lens collection if you prefer one over the other."
Finally Canon caught up to it in the APS-C flagship line, since the D200 was launched the X0D series have been failing to deliver to the competition.
The new viewfinder, is finally level with the D300s. The Video Mode is better for almost all aplications, as it is the 18Mp (still awaiting DxOMark results) and the fps slightly better (equal to D300s w/MB-D10), the menus are much better compared to the last X0D models making it almost as configurable as the Nikons, which still holds a good head in this aspect. The AF system is a big improvement over other Canon, but also still under par with the CAM3500 51-points from Nikon and with regards to metering the Matrix II with 1005 pixels seeing color and with D (distance) information from lens is still the unbeaten champion in the arena.
Nikon users are used to these specs (all but the video) since the release of the D300 more than 2 years ago (announced 27-Aug-2007). Finally Canon users can enjoy something similar, which will also push Nikon to update the 2yo. plataform. IMHO it is the best announcement Canon has made in the last years, and even being a Nikonian at heart I finally have a Canon body to recommend to my students that come with a big Canon lens quiver and background.
Good Luck!