Obama has 1889 total delegates.
If the remaining primaries break in the following way,
State | Obama/Clinton | Winner | Obama Delegates |
KY | 40%/60% | Clinton | 20 |
OR | 60%/40% | Obama | 31 |
MT | 56%/44% | Obama | 8 |
SD | 54%/46% | Obama | 8 |
PR | 44%/56% | Clinton | 24 |
then 92 pledged delegates will be awarded to Obama from the remaining primaries.
That gets Obama to 1981. Unfortunately, 40 of those delegates come after the May 31st Rules Committee meeting where the FL/MI issue will be taken up.
Obama would need 44(19%) more super-delegates out of the 235 uncommitted super-delegates remaining. Edwards also has 19 pledged delegates and if they all go to Obama then Obama will need only 25(11%) more super-delegates out of the remaining 235. Either way this goal is attainable and likely.
According to Donna Brazille, if Obama gets to 2025 before May 31st, then Obama will have won the nomination and the May 31st Rules Committee meeting will be canceled. That would require 84 super-delegates to endorse by May 31st.
Edwards endorsement gives permission to other super-delegates to bring this to an end. Thank you John Edwards.
Edited after slash196 comment.