Microsoft isn't taking that public a route but it has issued a statement saying:
We oppose the passage of the SOPA bill as currently drafted. We think the White House statement points in a constructive way to problems with the current legislation, the need to fix them, and the opportunity for people on all sides to talk together about a better path forward."
It is interesting that some are taking action and others are simply putting out statements. I guess the statement is all that's needed in this instance.