Sadly, I wish I had info on this. Instead, I just have wishful thinking and that feeling that this could really be a killer app. I mean, sure it wouldn't support as high a resolution as a laptop, but it would also mean that public speakers wouldn't have to lug around a laptop. There is a little problem with wires, since iPod Touch doesn't support BlueTooth, but maybe with a WiFi remote of some kind or some kind of wireless video transmitter.
That said, Apple should consider releasing "player" versions of Keynote and/or possible the other iWork apps if they have not. If only to encourage eating in to the hegemony of "convert to MS Office formats" if you want to share something with other people.