To you, Obama's the presumptive nominee (evidently not yet to Hil -- her choice).
But he hasn't yet reached the magic number.
Until one of them does (and I increasingly presume it will eventually be him, despite this >2:1 Clinton blowout), and as close as the count remains, it's simply not reasonable to demand Clinton concede. Time enough for that once either 1) Obama manages to put it away before the primaries end (I believe his campaign predicts he will in Oregon), or 2) all Dems have voted, at which point there's no reason for further delay in superdels making up their minds (again, presumably putting Obama over the top).
Thus fulfilling your desire.
Leaving one to wonder why you and fellow Obamites are so intent on truncating the process, disenfranchising Dem voters in remaining primaries (like me; am I wrong that that also includes you?), in the process tossing out the window the quite significant advantages (I've spelled them out before if you've been paying attention, so won't repeat here) of letting us all vote meaningfully since the race remains technically undecided.
One would almost think you lack faith in your candidate.
Hate to say it, but it kinda reminds me of the GOPers determination to prevent all the votes from being counted in FL 2000 once a "total" that put them nominally ahead had been reported.
As long as it remains technically (i.e., mathematically) undecided, let the voters vote, say I. I increasingly see substantial Dem advantage and no significant disadvantage in doing precisely that.
Those who've drunk deeply of 16 years of the VRWC's media-enabled Clinton=Satan (THEY SHARE A COMMON FINAL SYLLABLE!!!) kool-aid will, of course, see it differently.
But I'll maintain my choice to continue my residence within the Reality-Based Community.
