I would be very surprised if Sony kept the cheaper to produce 80GB PS3 at 600 USD after the 60GB model is cleared.
Think that in Europe the 60GB is already the cheaper software emulation model, and here we got a special pack with 2 sixaxis and 2 games for the 600. I believe the motivation behind these actions is they needed to push sales first, and as a nice side effect get rid of the old model. Not the other way around.
The marketing is just brilliant, people know the 60GB is a better machine (hardware emulation, possibility to upgrade HD if needed anyway, and more than 20GB, of course) so it creates the urgency to buy it soon. Then the stock is bigger than expected, but the urgency is kept since nobody really knows if today is the last day, sales are kept high. Then, when the stock is finally finished, surprise! the 80 is lowered to 500 USD with at least one good game and let's say the new sixaxis. More sales to come, since then people no longer feel they missed the really good deal.
Not following this very logical path and keeping the 80GB as it is at the current price would freeze sales. Differently from many people around here, I don't think Sony is that stupid.
We'll see it soon, anyway.
