the solution to this is :

Create a standalone application that manage the MapPoint COM Component.

Create your webservice.

Implement a protocol (over TCP or UDP) between your web service and your standalone application :
- Standalone app transmits coordinates to webservice
- webservice sends back the image over TCP/UDP
- webservice gives this image back to other apps...

i think that is the better way but it seems that implementing a webservice around mappoint is forbidden by microsoft, isn't it ?

see ya