I'm going to go against the grain here: I don't like it. It's one thing for SO to be a user-to-user forum so that fellow developers can help solve problems, but I don't think it's really appropriate for reporting bugs and making feature requests for technology vendors (whether open source contributors or companies) to reply to.

It's hard to pin down exactly why I feel that way, but I think it's to do with the relationship between the users. On SO, the moderators are those who have proved themselves worthy in a general community sense. On a technology-specific forum, I'd expect the moderators to be associated with that technology. They should be able to close a feature request as "declined" (with a reason) or mark a bug as fixed, There's a level of power, responsibility and knowledge which has nothing to do with what the users are like in the more general terms of SO.

I think it's fine for SO to be one of the encouraged ways that users help to solve each other's problems, but I wouldn't want it to be the primary support forum for a technology.

EDIT: Something I should have said before: I would view this as a good use of StackExchange - if a technology vendor (or whatever) wants to host a specific site for their technology, that would be great. I just don't really want to see feature requests and bugs for every API in the world on SO. (I'm fine with "I think this might be a bug, but I'm not sure - what do you think?" type questions though.)

EDIT: I've just been speaking with Kevin Bourrillion of the [Google Java Collections][1] and [Guava][2] projects. He's recently announced that Stack Overflow should be used as *one* of the support mechanisms. From his [mailing list post][3]:

> Where-to-post summary:
> 
> - How do I?  --  StackOverflow! 
> - I got this error, why?  --  StackOverflow! 
> - I got this error and I'm sure it's a bug  --  file an issue! 
> - I have an idea/request  --  file an issue! 
> - Why do you?  --  the mailing list! 
> - When will you?  --  the mailing list! 
> - You suck and I hate you  --  contact us privately at [...]! 
> - You're awesome  --  aw shucks!

That sounds like exactly the right balance to me. Topics requiring "deep" knowledge and discussion are likely to be best on a specialist list - whereas questions which "dabblers" can answer easily would do well on SO.

I will be fascinated to see the degree to which this becomes a standard practice - and whether it will be different for commercial products vs open source.

  [1]: http://code.google.com/p/google-collections/
  [2]: http://code.google.com/p/guava-libraries/
  [3]: https://groups.google.com/group/google-collections-users/browse_thread/thread/9bc16709c9ad0bcf?pli=1