I browsed through the Windows Phone 7 documentation web site, and was unable to find if it is possible to write an application on this platform that can communicate with the smarphone's SIM card using APDU commands/responses (ISO7816).
Is this possible to use PC/SC or some other API for this, and if yes, where can I find some documentation about it?
It's not supported on the phone.
May be able to do it with interop unlocked, but then you cannot submit for the marketplace.