I am creating a tool that will allow developers to create a new type of
form.  My new form is derived from System.Windows.Forms.Form but has new
properties added and some properties are hidden.

Right now I am considering using an add-in to allow users of my tool to add
this new type of form to a project.  My add-in would make sure that there
was a reference to my library, add a normal form to the project and then
change the form so that it's derived from my form and not from
System.Windows.Forms.Form.  Is there a better way to do this?  Ideally, I
would like to have an icon in the "Add New Item..." dialog but I have no
clue how to go about doing that.  Is it even possible?

Thanks for the advice.

- Rhy