Who says that the PC you're streaming your WiDi content from couldn't also be a console? Consoles provide certain other benefits besides being close to your TV. A stable, consistent platform that can be optimized towards, for instance. The "always works without fiddling" capability that Windows still hasn't quite matched is another factor. A stable price that allows you to play all content available for that OS without worrying that your system might need another $300 upgrade is another. 

Even if it's somewhere else in the house other than right by your TV doesn't mean it wouldn't be a console anymore. Heck, I don't use my consoles hooked to a TV, they're right in my computer desk hooked up to one of my 4 monitors.

I'd love to be able to take my little 7 inch Blackberry Playbook somewhere else in the house and stream my PS3's video to it while using a PS3 controller. I already use my 5 inch Vita screen in a similar manner for some tasks.

I will say that aside from some indie games (Bastion, Binding of Issac, SpaceChem) and games from Stardock, I've almost entirely stopped playing PC games. My power-sucking $2000 PC is mostly turned off unless I'm doing a major project that needs all that computing power. For gaming, the only time I turn on the power sucking beast now is to play Fallen Enchantress, as all of stardock's other games work fine on my E350 secondary computer. I don't usually feel like drawing 300-450 watts to play a game when they play perfectly well on my 70 watt PS3 or my 40 watt E350. Streaming to a display would just exacerbate this problem as I'd be dealing with graphics that my PS3 could certainly be generating and sucking tons of power to do it.

I don't think the traditional Sony/Microsoft consoles have much of a future myself.

Rising dev costs+ trying to pass those costs onto the consumer= high potential to folks to just give up on them.  Hearing Ubi-style DRM may be coming to at least one of the consoles, and if that happens, Steam becomes much more attractive to folks, especially as mid-range PC costs lower.

WiDi is cool and everything... but I think we are just at the beginning of Apple's traction to overwhelm day-to-day consumer data needs.

There was a slide show I saw last month that has pretty much convinced me to abandon Windows development.
http://www.businessinsider.com/the-future-of-mobile-deck-2012-3#-1

I am tending to believe what I see in this slide show because of a combination of 1) Apple sales continue to impress 2) iTunes has huge penetration 3) iCloud is the only cloud service I am actually inclined to use, because it happens that all my mobile stuff is Apple. (put those 3 together, and I am sure I am not the only one going this route)

4- Other stuff

-I've tried to develop directly on Windows Mobile (I am a C# developer) and realized they just do not have their crap together if you intend to make money. (couldn't do it after I tried)
- Android is a serious pain to develop on (compared to Windows and Mac anyways), it IS fractured and I realized this before the slide show. Also google is the devil.
- Using toolkits like PhoneGap, you can focus on the most profitable and unified market 1st (Apple) and then port to the others far easier then writing native.

So while I am doing this, I figure why not port my C knowledge into Objective-C, I'll probably be good to go for 10 years developing native on Apple's platform.

Ultimately I would tend to believe that Apple isn't stupid and they have the advantage right now... so conversion to their control over your media is going to happen naturally for everyone anyways.

The only question I have is if Apple is going to be able to overrun the home gaming market. I guess we'll see soon enough.

@2:

You think Sony and MS consoles have problems with rising Dev costs... If developers were pushing PC hardware as hard as they push Sony/MS hardware, PC game dev costs would be through the roof. The static nature of the consoles has worked to keep PC development costs in check because most developers aren't building special PC versions that fully utilize the hardware, just console ports that are upscaled. 

Some companies including Ubi tried to bring always connected DRM to the PS3, but they've mostly abandoned it as a terrible idea. The next generation may have DRM that requires you to connect when installing the game, but I doubt they'll require always connected protections like they previously have on PC.

Of course, the debate comes down to... if they block used game sales, will they bring game prices down again?