I'm of two minds about the Senate's idea to refuse to seat Roland Burris, perhaps going as far as using guards to keep him from the Senate chamber.
On one hand, Blagojevich is the governor. Since the legislature did nothing, neither impeachment or rushing through legislation for a special election, to prevent Blago from making the appointment, it's still his job and his right. And given that the subtext of the criminal complaint is that he's crazier than a shithouse rat, he can't be fairly expected to stop doing it. Generally speaking, I'm priggish about laws and rules and consider them higher than politicians, and think that sometimes you just have to suck it up and follow them even when it's not convenient or even immediately a good idea.
On the other hand, this is a free country, and it's designed to allow people to do stuff which may or may not be constitutional, because that's how we actually determine what's legal and what's not. That's what happened with Lisa Madigan's attempt to remove Blago's powers, which she was criticized for--she tried, the court told her to shove off, and the world went on.
Right now it's just not clear whether the Senate can block Burris, and one way of clarifying that is to go ahead and do it and let the courts figure it out. Obviously this isn't a failsafe manuever, as we learned in 2000 with Bush v. Gore, which the Supreme Court decided was "limited to the present circumstances, for the problem of equal protection in election processes generally presents many complexities." Or, as The Poorman Institute calls it, "the legal principle of tap tap ne backsies infinitum."
Still, that's how the system is supposed to work, at least, and creating bonkers case law is part of the majesty of America. Pass the popcorn.
Update: Of course, there's also the general question of whether bringing a constitutional challenge to a court you don't like will create precedent you don't want, but that's a strategic issue well above my pay grade.
Update II: Nate Silver has a good roundup and discussion of the issue.