4...Nc6 looks unusual. I used to play the French Defense and don't recall seeing this recommended anywhere. Of course, this doesn't mean there's anything wrong with the move - just that it looks odd (to me at least).
An interesting thing about the following line:
1. e4 e6 2. d4 d5 3. exd5 exd5 4. c4 Nc6 5. cxd5 Qxd5 6. Nc3 Bb4 7. Nf3is that it leads to the exact same position as:
1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. c3 d5 5. exd5 Qxd5 6. cxd4 Bb4+ 7. Nc3which is a line I've played a number of times againt the Goering Gambit.
(MNb: you can see that this discussion gets moved to the
1. e4 e5 section if it is too upsetting to continue it here.
)
Here dom gives
7...Nf6 which, in my opinion, seems to be somehwat inferior to
7...Bg4 recommended by theory.
After
7...Bg4 the main line continues
8. Be2 Bxf3 9. Bxf3 Qc4 10. Bxc6+ bxc6 11. Qe2+ Qxe2+ 12. Kxe2 Ne7 13. Be3 O-O-O (=/+ according to NCO, but closer to = according to Emms in
Play the Open Games as Black.)
Anyway, just wanted to point out an amusing transposition which suggests an improvement on one of dom's lines.