carlosjuero: Virtual Box DX support is off and on - some games it works beautifully with (namely DX 6 and older in my experience), some games it just.. ahem.. fails. OpenGL games have absolutely no issues in Virtual Box though :); Anyone going the VBox route should make sure to install the Guest Additions from within the virtual box - this installs the video drivers that have DX support.
drmlessgames: Is DX supported on win98se guests? I've only seen that any kind of 3d support is enabled only on xp guests, and specifically direct3d, not opengl.
I think that DX may only have true support in Win XP+ guests - I don't have a guest setup right now with Win98 to test [lost my disks] but I think I remember reading something in the FAQ/Help File about that.
OpenGL works whether or not it says its supported (at least on XP hosts) - all my older opengl games I run on an XP guest work great, the only ones I really have to fiddle with are some DX based games.