Okay, guys, guys, let me clarify your thought process here:
You only want Nintendo to buy Capcom and all of these other developers that have gone up for sale the past few years for one reason: the only way Nintendo can get third party games is by buying the companies and turning them into either first or second party titles. I get it; you really, really don't want the Wii U to fail. Trust me, acquiring Capcom in its current state won't necessarily be a boon to anybody.
Now, Nintendo is a god awful fit. Quoting some projects from around the start of this millennium does not a good case make. Capcom's mature IPs in no way belong in the hands of a company so heavily invested in creating a family friendly system that the abomination known as Miiverse exists. That would pretty much put Capcom in the grave. But oh, you might get MML3, so it's totally worth killing off every other franchise with bad sales, right? Right guys? Right?
When it comes to Microsoft or Sony acquiring, I dunno. Microsoft might be the most likely of the three based on releases from Capcom these past few years, but we've already seen what happens when Microsoft takes over what was once a pretty good game development company. Sony, I honestly have no idea how they would handle it. Regardless, it might get more games on the PS4, but then you still fall into the trap of limited exposure to series by exclusionary exclusive rights, removing the competition from the equation. Arguably, these sales issues wouldn't be as big of an issue, as the types of games Capcom's markets these days are certainly more suited to Sony's or Microsoft's consoles, but there is a pretty great risk of sales taking a large hit if Capcom goes exclusive with any one of the big three.
Thus, the conclusion and most likely outcome: a third party should buy Capcom. Sega seems likely since their holding company would certainly have the funds to make it so. Regardless, as long as a third party gets it, Capcom can probably keep operating as they want to with hopefully some minor tweaks from above telling them that eighteen versions of the same Street Fighter game is overkill.