1) The Pandora has OpenGL|ES 1 and 2.
2) There is a pvr gles sdk iirc.
3) There are some graphics engines like Sparrow 3d (not using opengles), Penjin, There is wavebreaker, which is an expandable gles examplegame and of course quake 1,2 and 3 engines and Darkplaces etc. run on the Pandora with gles support.
, have a look into the development section and the wiki: pandorawiki.org.