Okay, while I was sleeping I realized that while SDL_SetVideoMode(),
combined with the SDL_ANYFORMAT flag takes care of video depth setting
(except for 1 and 4 bpp which might be good to support), it doesn’t
take into account the flags, which may be SDL_FULLSCREEN, or eventually
SDL_FLIPSCREEN. SDL_VideoModeOK() will tell you if the video mode can
be natively supported, which is a very useful thing. 
So, I’ll just re-export it to the API.
BTW, SDL is approaching the time when API stability and binary compatibility
is becoming important. Has anyone here made a commercial, stable, extendable
library before? (Not that SDL will be commercial, only that it may be used
by companies for their products)