TFS as a Workflow Platform

I was recently pinged by someone asking if TFS would be a suitable platform for building a hardware order tracking tool for his team.  The idea would be to create workitem types for orders and a state diagram to track the order from placement to reception.  You could even take it as far as asset tracking: assign "asset" workitems to owners and when you shuffle hardware around the team you just re-assign the workitems representing the hardware. 

I've also heard of people creating workflows with TFS to create a simple helpdesk system.  Granted, this is a little more directly related to software development than a hardware tracking system, but it's still quite a bit different than what TFS was originally designed for (in my opinion).

There are other workflow tools available.  But to be completely honest that I haven't had time to dive into the Windows Workflow Foundation yet, so I can't really compare TFS to it.

On one hand, I like the idea of pushing the limits of TFS workflow to other applications.  Why not?  I think many of the key pieces to make such an application successful are already included in TFS: customizable workflows, e-mail notifications of workitem changes, a rich object model for building custom interfaces, reporting, etc.

On the other hand, is it overkill?  Are you taking a cruise ship and whittling it down to a rowboat? 

I'm curious to hear about what other folks are doing with custom workflows for processes other than software developmen and how you think TFS compares to something like Windows Workflow Fountation for building a custom tool like this.  Does it help to have information such as helpdesk tickets in the same system as your project workitems?  It might if you're an IT department and you're generating new product features from those tickets...  Something to think about at least.