You can just do both, though. Use interfaces for polymorphism, to define the interactions between your objects -- and then, if you want, use inheritance as one possible strategy for code reuse.
I guess it's a little strange that they haven't tried to put IE on the Xbox--but I'm glad they haven't. The whole reason I have a game console is to have an appliance that is dedicated to video games. I have plenty of other devices that provide a superior browsing experience.
I'm an avid gamer and own both the PS3 and Xbox. I've used the PS3 browser, it's an unmitigated disaster of poor functionality and even poorer usability.
The Wii browser, having used that also, is pretty much the same, plus muscle pain.
I know a lot of gamers and have yet to meet a single person who uses the browsers with any sort of regularity. In fact, the only instances where people use browsers on consoles nowadays are when the game brings it up by itself (DLC purchases, news updates, etc), and even then it's always more painful to use than a native menu would've been.
You need to cite your sources, because from where I stand - which is that of an avid gamer heavily involved in the gaming community, I simply do not see any significant usage of console browsers at all.
> "Even when a tiny DSi has a very capable browser, smart phones have browsers. And a big gaming console from a supposed software company doesn't even have a web browser?"
The major obstacle with browsers is not platform hardware, it's usability. Smartphones and the DSi have browsers because the web is (as we discovered with the iPhone) very easy to navigate with a touch device, particularly a finger-driven touch device.
It is significantly less awesome when it's driven with a joystick. In fact, the experience is downright terrible. Implementing a browser on a console with joystick (or Wiimote) controls is a waste of time and energy, and can only serve to tarnish your brand as your users struggle with why the hell you implemented such a dumb thing.
"The PS3's browser has a 0.04 share of the 'internet market', a miniscule proportion when compared to, say, the PC's 88.7 percent majority, yet it's a figure which sits comfortably ahead of the Wii's 0.01 percent."
Granted, those numbers are horribly out of date, but it would seem to indicate that the population (at large) does agree.
I believe Live Mesh has an OS X client now. I tried it (on both OS X and Windows), and while it has most of same basic functionality as Dropbox, I found the interface off-putting.