We have a single solution which contains one webapp project and some accompanying projects. Our TFS 2010 is building this solution every night and deploys the webapp to an I
One option would be to write this in a MSBuild task. In this way, you could support multiple IE unlimited webapp deployments. I have yet to port over our existing proj files that do this which is why I haven't ran into this issue. Anyway, here is an article that outlines that process:
Article
Hope that helps