for 500 bucks I think Sony could do most of what you said. Sony went with the too high price tag last gen and learned their lesson that bragging about potential capability for a while is good marketing, but eventual people will require proof that the extra cost provides a substantial benefit.
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut