The Drupal community traditionally clustered around Drupal.org. While surely there will be a community around drupal.stackexchange.com I am really curious on how can we channel these people back to drupal.org where they can contribute in the many ways drupal.org lets us: code reviews, handbook page, answering questions in the issue queues, bug reports, etc.
Ideally Drupal Answers would be a part of drupal.org. The only problem is that with a community as big as Drupal it will take a long time to form the consensus needed to get something like it there.
I'm sure you know there have been some talks about this in groups.drupal.org, but to go from there to actually have an implemented solution for asking and answering questions that's useful and organized might take as long as 2-3 years.
So how can we bring people back to drupal.org?
I'm not sure how many people there actually is channel back to Drupal.org. This site currently have around 130 of what SE calls avid users. That is a user with more than 200 rep. This is actually not much rep, but it is high enough that you have to make an effort, either being a regular user or creating some good answers or questions. Of those avid users, I believe most of them like yourself are already contributing to drupal.org. I think it would be quite rare to find some one experienced enough to answer questions here regularly, that isn't already active on drupal.org in one way or the other.
What we do already it to point people to the issue queue of a module if they encounter a bug instead of answering it here. But it's actually rare that this happens.
We do get some traffic from google, about 2k or so visits per day. The only reason we get this traffic is because right now this site fills a need that drupal.org doesn't. You can get a quick and easy answer to your question. I'm not sure that we can or should try to channel these people back. But I guess they won't be part of the community around this site anyways. If they don't come here, they might go to SO, a random blog or some other place.
Actually there is something that can be done to channel people back to Drupal.org, but this is not actually possible in a beta site.
In other SE sites (e.g., Super User with Community Promotion Ads - 1H 2011), I saw a question on their meta site asking to provide an image and a link that would be then shown as ad in the main site; the most up-voted ones will then be used in the main site. As far as I recall, on MSO the ads where about projects under a GPL or similar license.
If that would be done for Drupal Answers too, we could create an ad for a particular initiative that is important to Drupal.org, or we could put an ad for a project (module or theme) that needs some care, and that is maybe interesting for Drupal.org because it is going to be used on Drupal.org, and there are bugs or improvements to be done for the project. The ad could even link to a page where a list of initiatives are reported, and that link could even take to the group that is used for such initiatives.
Edit: Now we have it too; see Community Promotion Ads - 2012.
I think that 'answering questions in the issue queues' is a real weakness in D.O. the redesign didn't address. There is still no email notification of answers happening. So I am guessing there is no notification of questions either, which makes it really difficult to use to get the answers; therefore, there is a migration to an easier platform, such as drupal.stackexchange.com.
D.O. is great for filing bugs, and let the maintainers know what is going on, but I really don't think it functions as a community. IRC does a good job if you happen to be in the right time zone (I'm not, so it's really quiet when I get on it). These are just my 2c.