I added optional arguments to "isObjectInCollision" :

static unsigned int collisionList[MAX_COLLISION]; // objectId list of other physics-objects in collision
int nbCollision = physics->isObjectInCollision(objectId, collisionList, MAX_COLLISION);

I also added a function to set/get physics-object user pointer, which is the entity pointer in MEngine by default,
so you can get the entity pointer of the physics-objects by using :

for(i=0; i<MIN(nbCollision, MAX_COLLISION); i++)
{
    MOEntity * entity = (MOEntity *)physics->getObjectUserPointer(collisionList[i]);
}

I don't think there is, all I can see is isObjectInCollision, I think I need to loop through every object in the seen and then test collision... is this right? :S