You could display a much smaller web game while the main game loads. The trick is finding that proper balance where people are entertained long enough for the real game to load, but not so much that they'll want to keep playing the loading game afterwards. I, for one, can't wait to be waiting for a loading bar for a loading game to play while the main game loads.

Or how about this: Game Loading Lobby MMO, where you can hang out and chat with everyone waiting for their real game to load - IN 3D!. Maybe you can break out the character builder and have people do that, then get dumped into the MMO lobby while they wait for game assets to load.

Or you can just put a reddit iframe above the loading bar and call it a wrap.