I think Microsoft could definitely find some success if they can manage to make Europeans do the same kind of thing with national or maybe even better European soccer (or both) as the Americans do with NFL. There are fantasy soccer leagues here and there, same with F1 as well. Already for European and World Championship football, setting up pools and betting some money on the outcome of all 'last 16' matches is very common in most European countries as far as I know.
On the other hand, I'm not sure how well this would work against similar applications that allow you to do the same using tablets and smartphones, which is the current trend. They're not less useful for this, so Microsoft will really have to get the Xbox versions right in order to allow this to work during the actual broadcast of the matches and somehow match the overlays in a nice, realtime way. Possible, but very hard, I think.
TV in Europe, as has been mentioned here and there, is difficult because there are so many different standards. I have a cable box that this could work with (definitely one of the crappy Cisco ones that technically work well, but have incredibly crappy user interfaces), and because these box-makers are so incredibly bad at making a good UI, they would stand to gain a lot if they cooperated with Microsoft to get this to work properly. But the big trend which has progressed quite far at least in this country (and I think also in the UK) is for TVs to have all this built in, which means you can't put a box inbetween anything. So this would definitely require cable companies to move forward with services that any app in the home network can tap into. This would be a great step forward, but that would also allow any device in the home to make the most out of it, and would make the HDMI in superfluous. Even then though, it could work rather well as an input for a last-gen console. Imagine, having your PS3 plugged into the HDMI in of your Xbox One, and you could game on that while using the Party chat, Skype and other features of the Xbox One in an image overlay. Could be interesting enough.
WinRT was something I claimed would be a no-brainer for Microsoft a long time ago, and it is interesting to see they went with it in a big way. Although we don't know that many specifics, the fact that WinRT appears to be getting nearly 3GB to work with is certainly encouraging.
Of course, the downside is that this memory is not available for games. But Nintendo has shown us (more with the Wii so far than the Wii U, mind) that hardware and power aren't the most important factors - if you get your software and services right, then hardware performance is secondary. Now it's a matter of waiting and seeing how much Microsoft can bring to the table.
The whole Cloud concept as Microsoft presented it is interesting as a concept, but if you look at it from a software designers perspective, I think it's a bit of a nightmare and Microsoft really haven't thought it through enough yet to convince me at this stage, with their 'you'll have 3 virtual Xbox One's available for every real Xbox One'. First of all, it just seems really expensive (as someone who's seen everything from Terminals and VMXs / AS400s to every hybrid form we see today, I still believe more in distributed than in hosting as being the more efficient and flexible solution. Hybrid forms can be interesting, but the virtual machine setup seems more interesting for accessing your 'Xbox One' from other devices, which still has limited use in the context of force feedback controllers and Kinect then not being avialable), and secondly, quite hard to implement robustly on the software end, what with having to be able to still work decently if not available, using it for high latency tasks only, etc. I think if you could pre-calculate global illumination values or something like that using the cloud, that could be interesting just to do that with one big distributed calculation for everyone playing a certain game online (say, giving realistic weather and lighting conditions, maybe historically correct, for that time and location), then having three virtual Xbox One's do that just for one real Xbox One user, so to speak. But we'll see. Considering how long games take to develop though, I doubt we can expect anything useful at all before 3 years have passed?
I think they're support for upscaling, which of course they didn't explicitly discuss, is going to help them some, but the 360 had two strong gaming pillars last gen - good Live features that support online gaming, and good multi-platform gaming support. It's not immediately clear that what has been announced today is really a next-step, other than banking on gamers watching TV linked through their Xbox. It's still possible - there are some kids out there in the target range that have questionable boxes that allow them to watch more than they legally pay for, and they may really enjoy this type of linking up, so it's hard to predict this type of thing, but equally these are often not keen on paying something like a Gold service.
I think all things considered, ironically I am as curious about seeing how well the WinRT part of things will work with Kinect. This could be a weirdly important factor for casual use, getting way more useful apps for games, media streaming and what not than any such device would have gotten before, with one of the best kind of gesture based UIs available.
Whether such a UI would then really compete with actual touch on a tablet though is still a big question, and whether Smart Glass could make up for that is also still an unknown. The latter would need to be able to do what the Wii U tablet does, which it may be able to do (no reason why it can't do what Sony did with Remote Play and the Vita), but we've not seen anything like that yet.
Many questions remain, and now it's a long wait until we get to see more at the E3 conferences.
Even as a die hard GT fan though, a next-gen Forza at or close to launch is enough to make me want one (part of the reason why I've had all versions of Xbox so far).