I was going to answer those points Cos, because I have both machines reserved, but I'll just say this I don't have confidence in waggle/motion technology. I wouldn't care if they managed to hide the camera, I just don't like the idea of substituting my entire body for my hands. I go to the gym, I go to school, I go to work...last thing I want to do at home is jump around or wave my arms around to switch channels. I thought Kinect was a joke once I got over what I imagined vs. what was delivered. I don't like the motion direction and I don't prefer that direction. I wish they would so gung ho about chasing after the Wii's pot of motion gaming gold. So the inclusion or reliance on that motion technology is a negative to me, not a positive. I'm glad Nintendo moved away from motion with the Wii U as a matter of fact. I also PC game, and I don't like motion on PC gaming either. Remotes are more efficient and take far less effort. In the time it takes to press a button, I don't want to say "turn channel" instead, and I certainly don't welcome my friends or lady to change the channel with their arms/voice either. I know these things from experience, and I wasn't pleased to beta test the first kinect as it were.
It also is well documented that while they share very similar architecture's this time around, it's also well documented that one machine is more powerful under the hood than the other (this is probably the wrong forum to go into details to be honest), the issue is whether that extra juice that one machine has over the other will be a major variable down the road. I was tempted to place a few technology links, but I opted to refrain as this is a fun lovin' audio forum.
You are right, with regards to Blu-Ray playback, they do seem the same on paper as of right now, but we've been here before with earlier consoles. To answer the question about how different could the Blu-Ray players be in the new machines? We can use history. Before the Xbox and PS2 (1999-2001) came out, there was this belief they would have the same DVD playback. There was differences, quite a few actually from True Blacks to features. That same assumption again happened in 2005-2006 with the releases of the 360 and PS3. I would point to case studies of the DVD drive in the Xbox and PS2, and the DVD abilities of the PS3 (also Blu Capable) and 360 as a reference to differences. From interface, to options, to release official remotes, to ease of use, to gamma, to even sound...there were quite a few differences that some would squawk at, others wouldn't care about. Some people like 7.1 surround sound support, others were fine with 5.1, etc. Some would call the differences between those machines minute, others would say those differences are extreme enough to take notice as they find them very unappealing.
That all said, I do want to stress that I feel that we won't know differences until they release and this discussion is more on the fun side...and I'm looking forward to fiddling with both of these gaming doohickies in a few months when they launch.
