I'll update this post with more information and links, as and when they become available.
Here are the specifications:
- 18Mp APS-C (1.6 Crop)
- 8 frames per second
- A new auto-focus system, including 19 cross-type sensors
- ISO 100-6400, expandable to 12800
- 100% viewfinder coverage, with horizon assist
- Dual Digic IV processors
- Full HD video, including HDMI output and external mic input
- Built-in flash, with wireless sync to other flash units
- A revised 3" LCD 920k screen
As for a UK price-point, that's a little bit of a tricky one. It's not clear yet whether there will also be an evolution for the 50D (presumably the 60D?), or whether the 7D is the replacement. It's also serving largely different needs to 5D Mk II which suits landscpaes, weddings and portraiture, with its higher resolution and full-frame capabilities. A quick look at Camera Price Buster this evening (31st August) has the 50D body at £730 and the 5D Mk II at £1868. And the closet rival from Nikon would be the D300s (£1270) so I'm guessing somewhere around the £1600 at launch to grab the early adopters open wallets?
(update: I was close - it seems to be around £1700, albeit a lot are throwing in extras!)
The UK has got availability now: