The SONY A550 w/ LiveView is not a replacement A700. It is more of an upgrade path from the A300 or A350.
The new possible
A7xx may come with video ... it's a tough call. It looks to be a while before it arrives. More than likely, after Christmas.
The new A850 is an A900 rewrite ... so either camera is about the same. They are effectively FULL FRAME A700s w/o the built-in flash. A very good choice, no matter what.
