I know about the support article from MS, but that uses interop back to plain ADO. I really can't believe they would not provide a managed code alternative that works with ADO.NET. Furthermore, the DbConnectionStringBuilder class in ADO.NET 2.0 starts to solve the problem, but stops short, like Frank Costanza on a drive through New York City. That class gives us some capability to build up the connection string, but none to visually build it up, much less edit a connection string in-place in the config file.
After way more time searching around the Internet than I care to admit, I'd like to think that I'm missing some simple link, but it looks like MS expects every single .NET developer to implement their own Connection String Wizard from scratch. Feel free to reply if you know of any pre-built solutions.
Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.