Since .NET is your platform, you might be well served to have a look at ASP.NET Master Pages (http://msdn.microsoft.com/en-us/library/wtxbf3hh.aspx#Y889) if you’re not familiar with it already. It decouples content and presentation using the same design patterns that most web frameworks do in that you can have different layouts with common elements, but you have control over the functionality each UI component. In this case the Content control allows you bring in content any way you like, including from a DB if you design it that way. What you may want to do is to publish XML to your DB and transform it on the .NET or maybe XHTML and bring it in directly. I have not personally done this, but others in my organization have.
dtaylor, thank you very much for your answer. I am familiar with Master Pages. Also, I am familiar with the database publishing you just described, however, the database publishing (bringing the entire content to the database and then presenting in to the .Net publishing site) represents the Application Based Model, not the Component Based Model. I need to be able to fire up .NET in portions of the web site. In other words I have to somehow bring the .NET INTO the CMS, to use it only in several pieces of the CMS.
Please let me know if I made myself clear or have misunderstood you