Question: I have a business object that compiles into a DLL that handles all calculations for my system for concepts such as eligibility, etc. The object also handles the connectivity to the DB via some wrappers around it. 

Is there anyway to take this .NET DLL and use it as a datasource for a reporting services report (SSRS)? We don't want to have the logic in multiple places.

**EDIT**  

What about exposing the functionality in a webservice in the web app itself and having the report connect to the web service? Anyone done this before? We are using asp.net MVC for our web app if that helps.

Answer: 
Your probably going to have to do this with the Report Viewer Control, as I have not ever seen an example using the reporting web service.

<http://www.gotreportviewer.com/>

Here is the section on using Object data sources:

<http://www.gotreportviewer.com/objectdatasources/index.html>

These can be conceptually similar to ViewModels in MVC, so you would have to build ReportViewModels™ to handle reporting requirements.
There are two ways to get your data to the report: WebServices and Custom Data Processing. there is an excellent book to get you started: <http://prologika.com/Books/0976635313/Book.aspx>

After reading the related chapters I was able to easily use both techniques.