There are 408 pledged delegates yet to be aligned by primaries in the few remaining states and territories. Very likely that will split very close to evenly (my own prediction is that Obama gets 205 of them and Clinton gets 203 of them; the leaked spreadsheet predicted 208 for Obama and 200 for Clinton). Either way, if the voting goes roughly half and half, that puts Obama where he only needs about 89 of the 285 remaining super delegates.
Super delegates are deciding at a pretty steady trickle of a few per day, and they are coming in almost evenly between the two candidates... which should put Obama over the top in late May or early June.
May 3rd: Guam probably gives them each two more pledged.
May 6th: Indiana probably gives Clinton 38 and Obama 34
and North Carolina probably gives Obama 63and Clinton 52
Obama will only need 190
Clinton will only need 335
adjust both numbers for a few more super delegates
May 13th: West Virginia will give Clinton 16 and Obama 12
Obama will only need 178
Clinton will only need 319
again, adjust for supers
May 20th: Kentucky will give Clinton 31 and Obama 19,
but Oregon will give Obama 28 to only 24 for Clinton
Obama will only need 131
Clinton will only need 264
there is a 12 day break until Puerto Rico,
a very good chance that the trickle of super delegates declaring endorsements will probably pick up pace
June 1st: Puerto Rico will likely give Clinton 29 and Obama 24
Obama needs only 107 (minus the new accrued supers)
Clinton only needs 235 (minus accrued supers)
June 3rd: Montana will probably give them both 8 delegates
and South Dakota will likely give Obama 8 and Clinton 5
Obama needs only 91 (minus accrued supers)
Clinton needs only 222 (minus accrued supers)
At this point, it is likely both have accrued ~40 more supers each, and there are no more primaries. I am guessing the remaining super delegates declare now that voters are done.