Hi,
Problem with WineD3D on top of WGL is that we lost many of usefull APIs I think WineD3D on top of x11drv (as WGL on top of x11drv) should a the better way
WineD3D on top of WGL has the advantage that we can use our D3D libraries in windows too. This can be useful for testing(no other libs interfering), and it might come handy to use gl for D3D games in windows too, like d3d10 on xp once we have d3d10 support :-) . I personally prefer the way to support glX, wgl and agl in wined3d directly, without using wine's wgl or x11drv.