Presenting the latest CVS update:
http://www.libsdl.org/cvs.html
The biggest change in this update is that DirectDraw is not initialized
on Win32 when creating an OpenGL mode. This change alone doubled the speed
of the testgl example. It should also now work on the Voodoo series of
video cards. I also made some changes which should let SDL_OPENGLBLIT
work on Win32, but the texture doesn’t seem to be updating on the G400,
and I haven’t tested the code on other systems yet.
David Hedbor also contributed code implementing the SDL_WM_ToggleFullScreen()
and resizable windows on BeOS, thank you very much! 
And last, but not least, Michele Bini submitted code enabling the default
320x240x8 video mode in the Linux SVGAlib video driver.
Enjoy!
-Sam Lantinga, Lead Programmer, Loki Entertainment Software