Upgrading From IIS 6 To IIS 7

Hi...I need to know when upgrading from IIS 6 to IIS 7...What are things should be taken care of?

I am talking about VB.NET Web Application.

For Example,

1. How it will affect the maintanance of the application?
2. How it will affect the deployment of the application?
3. What are the feature / advancement in IIS 7?
4. What's the difference between IIS 6 and IIS 7?
5. What are the points should be taken care while upgrading?

Thanks.