Dark: You're over-looking the fact that most people already have appliances that do everything that the PS3 is said to do. People aren't going to fork over $600 when they already have all those capiblities in their homes.
The big Plus for movie enthusiasts is that the PS3 will play Blu-Ray movies.
At this moment, a PS3 is actually cheaper ($650) than a Blu-Ray player ($999). This is one piece of credit I will give Sony, for providing somewhat more affordable access to breakthrough technology.
The counter argument is, of course, that prices for Blu-Ray players will drop to reasonable levels in a short time, leaving the PS3 overpriced once again, unless Sony follows the market trend of the Blu-Ray player.
In theory, the PS3 should cost More than your average Blu-Ray player because the PS3 is a Blu-Ray player And More. At this point, the PS3 is actually in a very good place in the Blu-Ray market, as it is breaking that economical rule, even if only for a short time. I don't think this will last, as Blu-Ray players are now forced to drop in price and increase in quality.
Overall, it seems that Sony will need to very Very careful with how it controls the price of its PS3 units as time passes.