You know, "never" is a long time. Why don't you give it a try? It's free. There are free 30 minute trials on all games and the PlayPack (the Netflix equivalent of games) is free for the first month; just remember to unsubscribe before it starts charging you.
And you know what is funny? Many people just like you have computers/consoles capable of running everything, and yet, they are using OnLive. They still use their computer/console, but they just love the idea of cloud gaming so much that they want to support OnLive.
OnLive is great. I have noticeable latency because I'm far beyond OnLive's set "worst case scenario" at 1000 miles from their servers (I'm at 5000+ miles), and yet, I manage to enjoy their services. The image? Well, let's say for me it's good enough. It would be much better if I wasn't 5000+ miles away. I quickly just took a screenshot from Metro 2033, see for yourself here: http://i.imgur.com/BEw5w.jpg
But I'm not the best person to ask, as OnLive officially only are supported in the US and I'm not in the US. If you really want to see how it works, then you should try for yourself, but you could also see some videos made by Saieno which are great.
Comparison of OnLive, PC and consoles:
Unboxing of the OnLive Microconsole:
It should be noted that these videos are a couple of months old, but OnLive has only gotten better since then.
Yes, I see how this is somewhat of a hindrance. Some of the latest reports from consumers that I've seen, showed that OnLive took 2.3 GB/hour. Personally this is no problem as I don't have a bandwidth cap, but there has been people urging OnLive to enable standard definition (Wii resolution) to help against bandwidth caps. OnLive has previously talked about standard definition, but sadly they have other priorities right now.
Actually I was under the impression that it was cloud computing that was up and coming, rather than home computers. I could be wrong though...
It is, right now cloud computing is in.
But yes, you can say your home computer is getting more and more powerful as time goes, but from a consumer standpoint, upgrading can be very expensive. This is one of the main advantages of OnLive: if you can use OnLive now, you can use OnLive next year and next year again and so on...
And one thing I can assure you wont happen within the next couple of years, is locally rendered AAA gaming on a tablet. HTC has hooked up with OnLive to bring cloud gaming to their smartphones/tablets. They are working on getting the OnLive wireless controller to work with the HTC devices, and in fact, they already have. Here is a video of Steve Perlman (the CEO of OnLive) showing it in action:
(jump to 2:36 for the wireless controller)