I agree with Alex. Although, it took a lot of convincing (over 3 years), our Director finally agreed to allow us to use DNN for our intranet work, rather than spend more and more on an outside custom solution. I moved into another area, but our Web Master, is using DNN 4.x for all of our current intranet development at the hospital. It does take some additional work and preparation, but no more than any other off-the-shelf product. One of the more useful 3rd party modules is a forms builder module, can't remember the name, but it's saved our Web guy a lot of work. Others are available too.
Now, speaking about the News feed module, there isn't any real user-friendly options for skinnning the module, other than the available skin containers, but you would need to give folks some way to do it. The module look-and-feel can be modified as far as the feed goes, but adding css support in the XSL, but, again, that's not something a typical user is going to familiar with doing. The older News module v3.0.1 is better suited to customizing XSLs, and is generally eaisier to support than the new module v4.0.1, due to the issues it has with validating, and trouble reported downloading various news feeds. Also, some support of intra-module news syndication is out there, too. Howerver, there are 3rd party news modules out there.
One other thing, we do integrate a lot of flash to the sites, which are custom created for various department needs. All in all, I'd say you could use DNN, but it isn't going to be something that can be used without lots of training, if you want the departments to own everything for thier portal. We take that into consideration, and build some standard looks, and allow them to add content, rather than make design desicions alone. We interview and get a list of their needs, and then work out the best approach.
Cheers,