Well the .bsp version header in kingpin maps is the same as Quake2's and sure enough it even loads a simple Q2 map less the textures and entities (Obviously different between the two games)

Heres an example ALL NEW deathmatch map for Kingpin.. How I went about it was to re ent the entity section (you'll notice the hacked up ents that fail to load if you set logfile 1 before you start).. 

At any rate its just a map full of shotguns and shells. You get the idea..
I did mess with putting in the flamer and ammo but its caused an invalid page fault. So there might be something weird going on with that weapon.

Re enting is the easy part (Just get your friendly hex editor and edit the entity block (look for the names in the other .bsps) taking care to keep the size of the block the same (OR you could edit all of that in the bsp header etc if you wanted).

The textures are much the same.. find the name of each texture and then replace it with a valid texture from the KP pak file again ensuring same lengths etc.. You do have a pack explorer right?

So if you can hack an old map.. I assume anyone familiar with a mapping tool can build a new  map from scratch and just compile it out as if it was a quake2 map. =)

Just set up your textures from the KP pak and then add the entities in by hand. 

Someone make something better than boring.bsp =)

Have fun,
Can't wait for Kingpin full to hit a local store. 

Examples of valid entities are

weapon_shotgun
ammo_shells
