Now that Stack Exchange websites are becoming more and more integrated, I was thinking it would be nice to have unified Stack Exchange profiles. These would be similar to an individual site's profile but would show an 'overview' of the profiles from every other Stack Exchange website. Perhaps, though not necessary, even show a 'combined' section which shows the combined reputation, badges, questions, answers, etc.
I feel that this would serve to decentralize individual site-dedication a bit. In other words, certain users wouldn't feel too bad about developing themselves on another site as well knowing that their work is going towards a metric that takes everything into consideration. Not that I personally feel that way, I'm just saying it could possibly be a solution to those who do.
I just think it would be nice to have an overview of someone's activity/contribution to the family of Stack Exchange websites. This way, instead of linking to my Stack Overflow profile and/or Super User, Server Fault, Programmers, etc., I can just link to one unified profile, perhaps located under the stackexchange.com domain.
This would also serve to show people new to Stack Exchange that these really are a family of websites. That way, if they're not necessarily interested in Stack Overflow itself, they may find a link to Cooking, which they're interested in.
Just a thought.