General, PS3 is $600 for the 60GB version and $500 for the 20GB versions. HINT: Get the $500 one. The PS3 uses traditional 2.5" drives without any proprietary-ness to it. So you can buy a regular joe 2.5" 120GB drive off of Newegg for around $90 and stick that inside your $500 PS3. That way, you can have a $600 PS3, but with twice the HDD space. PS3 will format it for you.
OR, you could buy a $10 (guess) 2.5"-3.5" connector cable and use a regular old 3.5" drive with your PS3. Note that it will be sitting outside the PS3 if you do this, so whoever tries should get an external enclosure. But still, 750GB Seagate Barracuda for your PS3, anyone? Only thing left to see now is what kind of Media Sony has available for snatching up; hopefully something rivaling Microsoft's Xbox LIVE!.
Oh, and the Wii is $250 here is the US.
Unless you pre-ordered one, good luck getting the PS3 for less than $1000 with all the things that retailers are going to bundle with it. And the Wii is bundling for around $600.