So do we have a Poser game mesh standard ?

Polycount alt to be ???

Texture size alt to be ???

meshes alt to come with what all Maps ?
Color Map,Bump Map,Occlusion Map,Normal Map,Displacement Map,Vector Map
Specular Map,etc etc ???

of course not

Who would define that standard? And for what purpose? And for which game engine? And for which target platform? 

Poser does not have a standard per say. Game engines do.

Typical game engine maps are diffuse, specular, shadow, (Bump, displacement, vector, or normals).  Yes there can be others as well.

Shaders in a game engine will either be GLSL (openGl) or HLSL (DirectX or CUDA).

Poly count in a game engine depends first on how it is stored. If it is 16 bit, your limited to 64K per wireframe. Max scene count (shown on the screen at once) can exceed 2 million in some engines, others will fall flat on thier face long before that. GPU speed affects this as well.

If your using Unity, wireframes are stored in 16 bit, so 64K is the max per wireframe. You can go higher, but it will be split into two wireframes. Any 32 bit style engine has more potential than most hardware can push to the screen.

In a typical game, you might have a few different versions of the wireframe (polycount) to be used at different distances from the camera. If your doing a multiplayer game, you might need to do this if there will be a lot of players in one area at the same time.

Texture sizes are scene dependant. If you run out of texture slots, or video ram, it isn't going to work. (there are acceptions to this, think of it as a general rule)

You can have a very detailed scene with one character in a room, but no where near that amount of detail in a scene with lots of different characters, things in the enviroment, explosions, etc, all happening at once on the screen. Textures can also be combined, and the UV layouts set up accordingly on anything in the game. Lots of objects sharing a single texture and procedural textures are an option, and often done that way as well.

All of this is also subject to what the engine is actually doing in the background at the same time.

So, all of it is a balancing act. The only real way to tell the max poly and texture count/size is to try it in whatever game engine (and platform) you are going to use. You would be suprised what you can get away with in a good game engine and a decent GPU.

Let's not forget Ambient Occlusion too.   I know all Orbx airports for FSX now have AO included as well in their rendering techniques to be displayed in-game.