I don't know about when we'll see releases, but I agree with there being a much smaller time gap between them. This would make a much more fair comparison of which one sells better and is more popular. as opposed to the 360/PS3 comparisons, which were more like the Xbox/PS2 comparisons, I think that when they release so far apart it's harder to compare the two because when you have a year between releases of course the one that comes out first is going to be more popular, sell a little more and have better backing in the long run.
I hope you're right on the more rigorous testing program prior to release (on the part of MS), but I hope that on the same note Sony Is a little more realistic on pricing when they release and not screw over the early adopters like they did with the PS3 by making them pay to recoup costs.
I think you're right on the part of controllers, I think they'll all be using motion sensing of some kind,though most likely along the lines of the sixaxis (oh, I just realized thats an ambigram, lol). as for the motion capture... IDK, I see it being as much of a gimmick as I do 3D; I hope it will simply be a fad that will eventually go away as it is seen as an impractical control device for traditional style games (I mean really, how are you gonna control a platformer like mario, or a fps like COD, or an arcade style game like street fighter? are you really gonna wanna stand there and walk in place, jump, punch or kick for hours on end?) I think for certain games like dancing games and things like some sports games (a la wii sports) it's a fun and easy way to control things, but I don't see it ever being the standard control for a game, so I think if they do ship with the consoles I think it will be as an alternate bundle package (where you have a choice of say the core xbox package with a console and a controller or a bundle package with console, controller, and mo-cap). Regardless of what they all do I think that all the console manufacturers need to go back to putting 2 controllers in the console bundle. It really pisses me off having to buy a second controller separately...
On the note of media type, I don't see Gates' vision of a completely digital download world happening in the near future. I think MS won't have much of a choice but to put BluRay in their console. I know everyone thinks of it as 'Sony tech' but the truth of the matter is that it was a collaborative creation and nearly every major electronics manufacturer backs it. I mean ALL of Microsoft's drive suppliers for the current gen consoles are on the BluRay board of directors, and we've all been watching the horrible fail of DRM and the ongoing battle surrounding it. so unless MS can come up with an 'unhackable' DRM that can't be circumvented an all digital download console will be a miserable failure. Nevermind the fact that not everyone has a high speed internet connection (or even any kind of connection at all)... and yeah unless they run a total cloud setup where you don't even download the game data to your system, just a license that allows you to play it off their server, the HDD would be prohibitive in production costs (again nevermind the fact that if they did run cloud that they would need an insane amount of bandwidth and some serious server setups to be able to handle the insane load that a game like COD would put on the XBL network).
Now if they ran the console as a complete cloud system, then would you still have to pay for your XBL account like you do now? I know they have the silver and gold memberships, but the silver is total bull:censored: and gives you access to nothing worthwhile (and yes even when it's free it's not worth it imo). they would have to make some serious content changes to their free accounts and give far more access than they do now... otherwise that will be as much of a failure as the PS3 being released without an online network... I mean who would really want to spend $300 or more to buy the console and then not be able to get any games for it unless you paid a $X monthly/yearly fee, and then still had to pay for your games individually? At least as it stands now you can still get a 360 and games for it and play them and never get an XBL account. that makes XBL a luxury expense not a necessity like it would be on a cloud based system.
Now as far as the actual system hardware (cpu, gpu, ram, etc.), I think that they're really going to have to be at least one step ahead of the PC gaming hardware when they release in order to continue to have long console lifespans. using the method they do now where they release a console with specs on par with low cost gaming PCs that are a year or two old just won't cut it. I mean even my 4 year old dual-core was able to run Fallout 3 as cleanly, if not better than, my 360 did; and that was the day the game came out and my PC isn't even a gaming oriented PC, it was a total cheapo base model compaq with only a RAM upgrade from 1GB to 2GB. hell my wifes old vaio lappy was 4 years old when the 360 came out and it could still run games the 360 did when it was released... I think that in the next generation that using that same 'current low-mid level hardware' model will not be acceptable to people buying the consoles.
But then again, those are just my thoughts on it...