Let's start with the obvious: back when the Democrats were obstructing Republican nominees, the Republicans loudly derided their obstruction and threatened to change the Senate rules. The Democrats--the same who just followed through on those Republican threats themselves--objected to them in the strongest possible terms at the time. Much as I usually hold the "both parties do it" folks in contempt, here, at long last, is something that both parties actually do. The minority obstructs the majority, the majority rumblingly threatens to curtail its power to do so, the minority whinges about tyranny or time-honored Senate traditions with a tone of voice somewhere between grave disappointment and constipation, and it's all Very Serious.
I've now spent the last couple days watching conservative friends post democratic contradictions and liberal blogs post republican contradictions, as if the mere fact that the Republicans and Democrats routinely reverse opinions on the question actually constituted an argument for or against either position. The basic argument, as I see it, is that the present obstruction is sufficiently greater in degree that it amounts to a difference in kind. The old rules no longer allow for a functional government in our present circumstances, so change them. For the record, I buy it. The US system has too many potential chokepoints--contrast a parliamentary system, in which one side actually runs the damn government and then is judged at the polls on its performance. There's a continuum here, but we're rather too "choked" at present. Will I still think so when next--FSM forbid--a Republican is elected? Consistency demands it.
There is, of course, a more cynical way to view the calculation. Republicans, on the whole, block far more nominees--and keep them blocked far longer--than Democrats. Stifling the ability to do so would therefore be a net gain for the Democrats. One party's interest will--on balance, mind you--be advanced, and the other's set back, by the proposed rule change. The parties and their supporters have lined up appropriately, and marshaled arguments in support of their positions, but the real position comes from the interests and not the arguments.
Well, cynical mode off, now. What I would really like to see happen is to keep the filibuster, but make it an actual filibuster. In other words, no longer can any Senator simply place a hold on any bill or nomination. No--if they object to something and wish to delay it, then they can stand up and start talking. Then the vote happens when everyone is done talking. I'm not sure how this would work in a practical sense, however: victory would come when the majority party simply gets so tired of it that they cave rather than letting you go on. But that would happen whenever you expressed a willingness to go on that went beyond the majority's ability to tolerate/get things done. This in turn incentivizes grander threats and earlier caving, leading quickly back to the situation that we are in now, unless the majority leader had the stones to force the issue every time. So it's very pretty to think that something like this might be workable, but in practice the willingness to use whatever weapons are at hand to obstruct means that's unlikely.
Which is why, on balance, I'm in favor of the present forced disarmament, which everyone melodramatically insists on calling the 'nuclear option'.