If you can see SVO3 from SVO2 then I can not imagine them having it ready by March 08. From the construction I saw it looked like it will be fall of 08.
The two things are basically side by side. SVO3 is to the left of SVO2 (facing the runways).
Here's what it looked like on November, 7. And the white things in
this pic (same day) are supposed to be jetbridges - I wouldn't think anyone gets those ready a year before they plan to finish the works.
EDIT TO ADD: Note that I don't claim to know anything about construction. And I haven't flown out of SVO2 for almost a year now so I only get glimpses of the site from SVO1 across the runways whenever I fly to StPete. I know they are also building a connecting gallery between the two terminals which is supposed to be ready later than SVO3. Could that be what you saw?