Real world...the two machines are fairly indentical power wise. 80-90% of games will be cross platform when it's all said and done. Costs are too high now for most companies to be exclusive or to really flesh out the minute special abilities of each machine.
I'm hoping Sony's online offering is strong. MS has them whipped here for the time being and they have basically a 3 to 4 year head start. With the problems they are having (company as a whole plus blu ray problems), I don't think they have the ability to simply "purchase" an online system with money. It will take lots of development time and probably never reach LIVE this go around.
The HD disc formats are VHS and Beta all over again. I'd be hesitant to buy either one on it's own. PS3 has a BluRay player....great. I don't buy movies and in 2 or 3 years, players will be dirt cheap, even if they are dual format players. Not really something I care about, but I know plenty do.
I hope MS and Sony do well. Let them slug it out. It means they have to one up each other in an effort to get my dollars. That's what I want to see.
I'll report back on Friday after I've had some game time with Resistance. Looks like a fun game.