Profiles is an area I had a couple thought in as well. I don't think of this as a high priority area to work on, but while my mind is on it, I thought I would share.
To start off with, I should say I am perfectly happy with the way they are now. Less is more. However, some folks may feel differently. I can think of a couple of permutations of this off top.
Some folks may want to share their info with the communities they are part of. While I think there is a strong sentiment out there that email groups differ from a social network, and are not meant in the same vein, I think more options are never a bad thing, and for those that want a more robust profile, why not offer it as an option?
Another aspect of this thought is that even with the minimalist profile that exists today, some folks may wish to be more private and not share which groups they are part of. Stalking and harassment are very real online, and folks deserve to protect their anonymity on any service these days. Along these same lines, people who do want to share profile info may only want to share certain things about themselves with certain groups, Managing all your various data points on a group by group basis doesn't sound very practical to me though.
However, I think if you had the ability to create Alias Profiles which stood as a "mask" for your Main Profile in regards to a specific group, this would be a lot easier to manage. Then when you subscribe to a group (and at any point after) you could choose to be seen in that group using your chosen Alias Profile instead. This way you control your sharing per group without having to manage which item goes where on each field and complicate your Main Profile. Just make one you want for the group(s) you prefer.
Another application of this would be to be able to make characters for RPGs. Adds to the feel of the group if you can create an in-character persona for people to view. Granted, a wiki works for that as well, but folks could then easily re-use one in a second group without the need to copy paste.
Of course the email stays the same if the user changes profiles, so there's not true anonymity, but people clicking on the person could only get as deep as the user decides.
Just a couple thoughts. Like I say, low on my own list of priorities, but for those inclined to discuss the feature, these were a couple of "drive home" thoughts.