Daniel left some great comments in response to my brainstorming that I wanted to call out and respond to.  I think one of the problems with my post is that I labeled things as “transition“ plans.  Yes. I do believe there will be a transition away from public NNTP to another solution.  That, however, does not mean I'm not trying to find a solution that keeps in mind the reasons why people love NNTP.  We could have set up web forums already if that were the case, but we want to do this right.

Every .NET forum I've been to loads slowly. I am not really sure any single site can really provide the guaranteed bandwidth for the masses to access at the rate communities are accessed. One of the major benefits of NNTP is that it is considerably less pressure on the bandwidth. Not only is a lot of it offloaded to other repeater points, there isn't all the bulk of feature-flooded RSS or HTML involved.

I agree.  No solution is going to beat NNTP for speed an simplicity.  What we've seen though is a request for more features that simply can't be tacked on to public NNTP.  A lot of new developers only use Usenet because they are searching groups.google. and seem to prefer the interface and features that can only be achieved with a web forum.  Your the first person though who suggested that RSS wouldn't cut it.  Not that the download is any quicker, but it does allow for an offline state and then your speed of browsing post->post is only limited by the client. 

For anyone who is really interested in reading and responding, as opposed to those looking for answers(I get the feeling you were considering askers over responders when you thought about this), there are a few things that have to be satisfied:
1) the forum has to be very fast, I don't want to wait 5 seconds for a message to download and render every time I request a message, I do, after all, have alot to read. Someone who is simply looking for an answer isn't going to have that kind of trouble, they only intend on opening maybe a half dozen messages, not the hundred plus I am.

Agreed.  Perf is a priority whether you are using the web interface or not.  However, I'm not convinced that a web interface alone will be good enough for someone who wants to read hundreds of posts and respond to a good number of them rapidly. 

At times I post seven or eight times to a given thread in an hour, if I have to wait for a moderator to approve it, that progress drops significantly, potentially spanning the conversation out for days.

I'm implying post-post moderation so the posts would show up in real-time.

my main problem is in determining who defines whats appropriate on a community site, the site owner(Microsoft, asp.net admin, whomever) or the community itself? This applies to pre-post moderation as well, but it is pretty clear, IMHO, that it would be the responsibility of the site owner.

The ASP.NET forums have been going along pretty well with moderation from community members and MVPs that have been elected as moderators.  It should be easy for anyone in the community to flag a potentially offensive post as requiring moderation and the moderators to go through flagged post and be on the general prowl while they are on the system.  But yes, it should be the site owners responsibility to set the tone by explaining clearly what sort of behavior is tolerated and what isn't from the start. 

I'll touch on the perf issue one more time.  I'll assume Daniel is a user who loves working with outlook express.  How does this work as a proposed solution for Daniel and users like him?

Daniel visits forums.msdn.com for the first time.  Daniel registers for an account via the web interface.  At the last step of setting up his account Daniel is told to select a password for use on the nntp.forums.msdn.com server that has been set up with an NNTP service that exposes the forum content.  Daniel is then able to close his browser, open up OE and log onto the forums through the NNTP service.  He is able to read and reply on the private NNTP server and his posts will show up as from him on the web interface as well.  Danial does miss out on the advanced features provided through the web interface such as moderation and post ratings, but is able to maintain his current work-style. 

I thank everyone for leaving me comments.  The only bad feedback is no feedback.   AT: You requested that list of existing MS community properties and the pros and cons of each one. I agree, that list would be valuable.  I'm in the process of putting it together.