Just a sidenote: I'm not sure whether I should post this to serverfault as well, because some MOSS admin may have some info for me as well?

Additional note 1: I've found this document (Asp.net MVC 2 & Sharepoint integration) if anybody with sufficient expirience is willing to comment on its content whether this can be used in my described scenario or not.

Additional note 2: I've discovered (later) that Silverlight is supported in Sharepoint 2010 so I'm considering it as well. So if anyone would comment on silverlight integration as well.

A bit of explanation first (without Asp.net MVC/Silverlight)

Is it possible to integrate the two? Is it possible to write an application that would share at least credential information with MOSS?

I have to write a MOSS application that has to do with these technologies:

• MOSS 2010
• Personal client certificates authentication (most probably on USB keys)
• Active Directory Federation Services
• Separate SQL DB that would serve application specific data (separate as not being part of MOSS DB)

How should it work?

1. Users should authenticate using personal certificates into MOSS 2010
2. There would be a certain part of MOSS that would be related to my custom application
3. This application should only authorize certain users via AD FS - I guess these users should have a certain security claim attached to them
4. This application should manage users (that have access to this app) with additional (app specific) security claims related to this application (as additional application level authorization rights for individual application parts)
5. This application should use custom SQL 2008 DB heavily with its own data
6. This application should have the possibility to integrate with external systems as well (Exchange for instance to inject calendar entries, ERP systems etc)
7. This application should be able to export its data (from its DB) to files. I don't know if it's possible, but it would be nice if the app could add these files to MOSS and attach authorization info to them so only users with sufficient rights would be able to view/open these files.

Why Asp.net MVC/Silverlight then?

I'm very well versed in Asp.net MVC (also with the latest version) and I haven't done anything on Sharepoint since version 2003 (which doesn't do me no good or prepare me for the latest version in any way shape or form). This project will most probably be a death march project so I would rather write my application as a UI rich Asp.net MVC application and somehow integrate it into MOSS. But not only via a link, because I would like to at least share credentials, so users wouldn't need to re-login when accessing my app. Using Asp.net MVC I would at least have the possibility to finish on time or be less death marching. Is this at all possible?
I haven't done any serious project using SIlverlight, but I will sooner or later have to. So I'm also considering a jump into it at this moment, because it still might make this application development easier than strict Sharepoint 2010.

Questions

1. Is it possible to integrate Asp.net MVC/Silverlight into MOSS as described above?
2. If integration is not possible, would it be possible to create a completely MOSS based application that would work as described?
3. Which parts of MOSS 2010 should I use to accomplish what I need?