Sony owns the living room. PlayStations, Bravia HDTVs, Sony this, that, the-other-thing audio products. The Wii isn't a major player in the living room -- its an accessory. A very popular one at that, but nothing more. The PS3 and even the PS2 can be, and in many cases are, proven centerpieces in their role as media playback devices.
NPD studies have shown that some colossal number of US PS2 owners purchased it, primarily, as a DVD player. Something on the order of 70%, as I recall. %70 of tens-of-millions of households in the US... is a whole lot. From that perspective, I think Sony's decision to have the PS3 include Blu-Ray makes a LOT of sense.
Why Nintendo left DVD playback out of the Wii... I will never know. I can't even replace my PS2 as a DVD-player. I still use the PS2 more. WAY more. Weak... ...except when they bring on the Nintendo 1st-party goodness, that is!







