Stack Overflow, and most Stack Exchange sites that are currently flourishing, deal with open communities discussing technologies and subjects that are, for the most part, public domain or at least open for discussion.
Other communities are not so fortunate.
Take Healthcare IT, for example, a new site still in public beta that is struggling somewhat.
Firstly I invite you to read another post I made to explain the specific challenges facing a site on Healthcare IT.
Now the idea of corporate accounts or group accounts has been discussed here before in many angles. And I do agree with some of the arguments that were given stating they do not have a place. Stack Exchange is not a social networking site and to emulate LinkedIn or Viadeo would just dilute the purpose of Stack Exchange. I don't think that groups should be first-class citizen as this opens the door to many abuses.
Nonetheless I still believe there is room for allowing some sort grouping strategy to make it easier for users that are walled in to still participate to the community. I do not have yet the appropriate recipe or formulas fort his concept but I think it warrants another visit.
I also believe in the meritocracy that reputation system creates. This concept should be extended to groups in some way through the actions of their members during their active membership.
I think the solution lies along the lines of some extra statistics on individual accounts and some extra functionality for "administrators" of this group to allow them some targeted overview on the actions of the members.
Again I do not have the complete final solution just the idea, but I know that we should find a way to invite corporate entities to participate in the community. I am certain that we can figure ways to make this participation beneficial for both Stack Exchange and the group.
Note that I speak here of a corporate, but carefully crafted, solution that would be generic where corporate entities are just an aspect of it.