I wonder what this will mean, and who a good choice for the next pope will be.

It's really weird that he's stepping down - it hasn't been done since the Middle Ages and frankly if you're trying to leave a good papal legacy, anything that draws comparisons to the church of the Middle Ages isn't favorable. On the other hand, if you're going to by cynical about it (and goodness knows I will) it could also be a play by an aging pope to exert greater influence over his successor than he could if he died. But who knows, really.

As for the next choice, I think if they wanted to be really clever they may want to pick one who is closely connected to the developing world. Cardinal Turkson of Ghana would definitely be an interesting pick, for example. Considering that Catholicism's greatest spread has been across the developing world thanks to their organized missionary work, it seems sensible to represent the people who they are converting in the largest quantities. Thus, someone attuned to the struggles of those areas in particular would probably win a lot of trust and goodwill. My vote is, look to Africa or South America for a serious contender. That or they'll shock the world and pick an old European guy.