I've chosen Bazaar as my first DVCS. Ed asked me why, and the answer turned out to be quite interesting (to me).
Firstly, why not git? Well, I am in general not a member of the linux world mainly because computers are for me (these days, anyway) a means not an end. I no longer enjoy installing this and (re)configuring that and (re)compiling the other just for the sheer joy of using up cycles and feeling as if I know something that others don't. Nor for squeezing out the last scintilla of performance, nor whatever it is that the 1337 do these days. I want a computer to do pretty much what I need out-of-the-box. That's why I'm a Mac user. So the idea that git provides the "plumbing" and then the "porcelain" (nice metaphor...) is built on top, well I'm bored already.
What does that leave? I head that darcs has these nasty performance cliffs that it falls off of, so no dice there. I have heard good things about Bazaar (specifically, that Nat likes it) so I'll go with that for now. So far, I really like it. Setting up exactly the distributed topology I need with the protections I want is proving to be a bit of a challenge, and the documentation seems to assume that I'm very familiar with...something...that I seem not to be (and I can't quite figure out what it is to go learn it, either), but so far so good.
I find myself a bit disappointed, though, that the FOSS crew have run quite so hard and fast with this. It's kind of a shame that people like Ed and myself can semi-legitimately get involved in a conversation about which DVCS and why. Summed over all the people like Ed and myself that's a lot of mental energy being poured down a black hole, across the industry as a whole. Especially since it seems as if there is almost nothing to choose between these tools. If only a strong industry player could have set the scene against which others could vary, but BitKeeper didn't (thinks: how much of this mess is really about sticking it to Larry McVoy "the man"?), and git hasn't, and now we have a soup of peers and all these nugatory factors to consider. What a waste.
PS: especially irksome is that I once had the pleasure of working with VisualAge for Java Micro Edition, which got all this pretty much exactly right a good long time ago.