You might want to wait there there are some reviews of it. Taking from the release of the Canon XTi, Nikon D80 and Sony A100 a little over a year ago, the A100 was the redhead stepchild of the 3. Although each of those cameras used the same (oddly enough Sony sensor) the noise performance of the Canon and Nikon stomped on the Sony A100, quite stockily bad in fact.. Considering how good the XTi and D80 performed with ISO 800 and above. The A100 also suffered highly in speed and features compared to Nikon and Canons offerings.
Not really sure how much money the A700 is going to be, but it looks like it has the same sensor as the Nikon D300 so it's probably gonna be a prosumer market camera. Taking from what I've seen the D300 offer, I am not sure this new Sony DSLR will be able to match it.
It is nice to finally see Sony start stepping away from their proprietary MemoryStick, although still used on the A700 they added a CF card slot too. Wise choice sony, nobody likes MemoryStick. Looking at the preview for this thing I also noticed it only has 11 point AF, which is far behind Canon and Nikons new offerings, (Nikon having 51 point AF)
I'm not saying the A700 is going to be a bad camera, but Sony has a tendency to let the market down. If it's around the $1700 USD range it has no chance in my honest opinion up against the Nikon D300, and then again if it's in the $1300-1400 I also believe it has no chance against the new Canon 40D although the 40D has 2 less MP is looking to be a better camera.
EDIT: Since typing this I have found out it goes for about $1500 USD. Which falls right in between two of Canon and Nikons best offerings right now. Unless it's magically $200 better than the 40D, I think this is just another bad Sony purchase.