First of all, let's see how this position is arrived at. This itself will help us evaluate the position and tell us whether Black can equalize, without even performing any detailed analysis.
[Event "Queen moves around, wasting time"]
[FEN ""]
1. e4 d5 2. exd5 Qxd5 3. Nc3 Qe5+ 4. Be2 Bg4 5. d4 Bxe2 6. Ngxe2 Qa5 7. b4 Qxb4
If we see Black's play, Black played a very peculiar 3...Qe5+, forcing White to develop a piece (Be2). Then Black attacked that piece with 4...Bg4. White continued development with 5. d4, chasing away the queen, gaining a tempo. Black was now forced to exchange the Bishop with 5...Bxe2, but White used that to his advantage by bringing his g1 knight into the game with Ngxe2. Now, f3 would be the best square for this knight, so Black gained something from this exchange. However, Black is tremendously lagging in development. Two of White's pieces are already developed, White has a strong pawn center, the Black queen has to move. After 6... Qa5 7. b4! White opens another line for his rook to come into the game at the cost of a pawn. Analysis will show that Black cannot hold on to the material advantage, but even without analysis we can simply assess this position as good for White because the Black queen's position is quite bad, the b7 and c7 squares are weak and White's piece activity is tremendous.
Now, here's some complementary analysis with Houdini 1.5 and Stockfish 4.2 which proves the above point. After 7...Qxb4, I initially thought of 8. Rb1, but it seems that after 8...Qc4! the Black queen finds a safe refuge. Hence the computer move 8. Qd3!, developing the queen and preventing Qc4 is quite strong.
[Event "White's lead in development is too much for Black"]
[FEN ""]
1. e4 d5 2.exd5 Qxd5 3. Nc3 Qe5+ 4. Be2 Bg4 5. d4 Bxe2 6. Ngxe2 Qa5 7. b4 Qxb4
8. Qd3 Qd6 9. Rb1 b6 10. Bf4 Qd7 11. Qf3 c6 (11... Qc6 12. Nb5!)
(11... Nc6 12. d5 Na5 13. Nb5 Rc8 14. Nxa7 Rd8 15. Nb5 Rc8 16. O-O Nf6
17. Rfd1 Nc4 18. Nec3 Nd6 19. Re1! Nc4 20. Rb4 Nd6 21. Bxd6 cxd6 22. Ra4 h5
23. Ra7 Qd8 24. Qg3 h4 25. Nxd6+ Qxd6 26. Qxd6) 12. d5 Nf6
(12... cxd5 13. Nxd5 Na6 14. Nxb6) 13. Bxb8 Rxb8 14. dxc6 Qg4 15. c7 Rc8
16. Qb7 e5 17. h3 Qe6 18. Nb5 Bc5 19. Nxa7 O-O 20. Nxc8 Qxc8 21. Qc6