I'm not sure breaking up M$ is really the right way to go. Does anyone really believe that M$ would not collude with the lopped off pieces under the table? They've shown they have no respect for the laws in the past. It may be better ot keep the slime in one ball.
How many lawsuits would the Feds have to file to keep the slime puppies from colluding? Breaking them into more pieces simply means there are more connections that must be watched. And even judicial remedies won't take those liars down. I cannot imagine the judge telling M$ no more Passport, no more Windoze CE, no more (fill in the innumerable markets they've infected). Even the judge demanding that OEMs supply competing OSes won't help because M$ will make threatening moves to keep them in line, moves that require the Feds drag'em back to court. How often could the Feds realistically do that?
I very much would like to see M$ be taken down by technical achievements of other companies or OSS. As it stands now, I think OSS has the only realistic chance. But OSS isn't big enough to threaten all the markets those bastards have penetrated.