Every single PS3 game will support the HDD - we already hear plenty of X360 owners complaining that the useable 13GB of space they have isn't enough and X360 games don't even support the HDD across the board.
Add to that downloadable content and not just game demos either.
Sony owns the biggest movie library in Hollywood, as well as a music label and 1000s of BC PSOne and PS2 games which all be offered for download at some point.
I don't even think 60GB will be enough.