I love the fact the Kinect sensor can do all the fancy 'Minority Report' stuff. I am 'meh' about using it for games, as I don't want a 'Wii' experience - but I do welcome it for talking to your games and bringing up HUDs, spells, you get the picture.
I think the HDMI in as well as the out is a great concept - but only if Virgin and Sky (and all the other Euro counterparts) are supported at launch. It's no point that being a US only feature.
The fast switching of the Xbox between apps, games and video is due to having HyperV (the same code from Windows Server 2012, possibly the forthcoming 2012 R2) and will support remoteFX - so when they blow that open and allow remoteFX supported computers to connect to your TV over a remoteFX initiated RDP session (remoteFX is supported from Windows 7 and up) I will be really impressed. It allows remote use of the GPU meaning some really impressive capabilities between PC and Xbox. For anyone that knows VMware, VMware View is kind of the same technology.
The trade in of games blows, I was disappointed at first but then I thought, you know what? I haven't pirated a game since I was at University. So maybe it isn't such an issue for me. They appear to let you share your games with 10 other XBL gamertags for a 'friends and family' type service.
The other thing is with the restriction of games in regards to trade ins. I hear this is a publisher controlled option, not a Microsoft one. Seeing how greedy Publishers are it would not surprise me if they (rightly or wrongly!) look more favourably on the Xbox for controlling 'their property' versus the PS4.
In regards to iOS, Android and Steam, and the way the PSVita controls its game library you cannot trade in anything you buy there - although I duly note it is digital only, not a physical copy - and this doesn't appear to peeve to many people. I think the way that physical media is actually traded, which is still a 'wait and see' kind of thing for the Xbox, will be a major selling point; or not.
I can't believe i'm going to say this but I think I might honestly go digital only downloads for this console generation, apart from maybe a few key titles i'd like the Collectors Edition of or something. Probably something like Mass Effect
Hardware wise I think they both have almost the same AMD x64 CPU. Graphically I think the PS4's higher bandwidth ram is will interesting to see. I think this will equate to better graphics for exclusive titles, and possibly dual platform games where the PS4 is the lead development platform.
Games that were shown. I think the Xbox had a better line up of games currently shown at E3 - but that doesn't mean to much right now, but games are what sell consoles.
In regards to live streaming the PS4 and Xbox both support it, using twitchtv for the xbox(? I think?) and uswitch for the PS4 so they are both matched there.
I think Microsoft illumiroom support makes me want the Xbox more, along with the better games and Kinect/social features.
I am pretty sure the Oculus Rift will more than likely have support for both consoles, I don't think Sony or Microsoft can afford not to, so that's a stalemate.
I honestly believe the next generation of Xbox smartglass with give an interaction to games that the current 'connect your PSVita to your PS4' won't be able to match. Sony need to connect up to tablets and smartphones using all major OS', and the touchscreen on the PS4 controller looked like an afterthought - I can't see that providing anything groundbreaking in regards to games or interactions.
So I've pre-ordered an Xbox, but i'll probably buy a PS4 also, and enjoy the exclusive games and experiences each has to offer.
And that is probably that.