I am wary of Microsoft here. Yes, Google may be a monopoly, and yes. monopolies are not good. However, MS is a convicted predatory monopoly. Recent happenings with OOXML in ECMA and ISO has shown they will do ANYTHING to get to their goals. Once they start in a sector, they will subsume it completely as soon as they can, using every trick they can to oust competition. For the classic example, refer to IE vs. Netscape, where the antitrust suit began.
And I would rather have two competitors to Google than just one combined one.