As an exercise i just looked back at the 2/6 leaked obama speadsheet.

contest, total delegates, projected obama delegates, actual obama result minus projected
LA 56, 31, +3
NE 24, 15, +1
VI 3, 2, +1
WA 78, 49, +4
ME 24, 10, +5
DC 15, 9,+3
MD 70, 37,+5
VA 83, 43,+11
HI 20, 11,+3
WI 74, 40,+2
OH 141, 68,-1
RI 21, 8,+0
TX 193, 92,+7
VT 15, 9,+0
WY 12, 7,+0
MS 33, 20,+0
PN 158, 75,-1
IN 72, 39
NC 115, 61
WV 28, 13
KY 51, 23
OR 52, 28
MT 16, 9
SD 15, 8
PR 55,25

thoughts:
1. the estimates have been very good.
2. the estimates give a 67 delegate win to obama and he has out performed them.
3. It looks to me like the nomination was won in the potomac primaries.