I think MS did the right thing whether or not it was intentional. Games don't take up a shit load of space and if developers stopped being lazy fucks and would build real-time cut scenes actually making use of that nice hardware then they sure as hell wouldn't need over 9GBs for a game because retarded pre-rendered movies wouldn't be sucking up space.
MS isn't making you buy something you may rarely use. I rarely watch movies and I know damn well that games don't NEED 50GBs so Sony fucked up by putting that shit in their console and driving up the price. Look at it this way, Sony could've dropped in a DVD drive and sold the damn thing for $400 and it'd probably be difficult to find PS3's on the shelves; sell a $200 Blu-ray add-on and considering stand-alone Blu-ray players aren't cheap, they'd be able to sell the add-on without a problem to the people that would want to utilize it.
Sony F'd up and now MS is going to drop 360 prices, $250, $350, and $400 for their systems so Sony still has a way to go before they catch up unless they can get some really kick ass titles.