If this feature is Google-specific, as in, it only operates on google results (by something within the Chrome code), then I think this represents a profound change in the generally content-neutral view of websites, and gives them an unfair competitive advantage which may pose regulatory issues.
<link rel=prerender href=somewebsite> and it'll render and fetch a page in the background so navigation to it will be fast.
Also, apparently prerendering automatically aborts whenever plugins are found on the page, so this may be bad since many slow web pages are slow because of the use of Flash.
I remember this had its controversy quite some time ago. I'm glad Chrome is taking it seriously, but I wonder what happened with the old implementation.
(Note that the markup was <link rel="prefetch"> and now is <link rel="prerender">)
It seems like a significant shift for Google to be releasing major search features as Chrome exclusives. I think they did this before with the personal blacklist feature which was eventually put into the web UI. (Can anyone fact check that for me? I never used that feature.) Should be interesting to see if this is the start of a trend. I know I'll probably switch to Chrome eventually if that becomes the only way to get the full Google experience.
This isn't a search feature; it's a browser feature. There's no real way for them to implement this in a cross-browser way; they could load a hidden iframe for the first result, but it looks like they're actually rendering it in the background, not just pre-caching it, so it wouldn't have as much of an effect. Other browsers could probably implement this just as well, eventually.
The salient bit seems to be: "The browser fetches all of the sub-resources and does all of the work necessary to display the page. In many cases, the site simply seems to load instantly when the user clicks."
I'm not sure if impression tracking gifs would be loaded (I'd hope not), but it doesn't seem to run any of the JS.
I imagine this as Chrome middle-clicking on links Google thinks you may want to see. They're opened in an invisible tab that replaces the current one if you click the link.
Just as Google Instant made AdWords more confusing, it sounds like link prerendering will affect all sorts of analytics.
And how exactly does the browser render assets without loading them? Is there some sort of time-traveling HTTP google is hiding under the curtain with this feature?
The docs [1] seem to imply that it will do everything that will look like an impression, presumably you (or your ad network) will then need to use the visibility API [2] or load your advertising as a POST.
How do ad networks track that the webmaster isn't opening ads in a hidden iframe now?
Edit:
Okay, it seems to be part of a new HTML API ( http://code.google.com/chrome/whitepapers/prerender.html ). Just add the tag:
<link rel=prerender href=somewebsite> and it'll render and fetch a page in the background so navigation to it will be fast.
Also, apparently prerendering automatically aborts whenever plugins are found on the page, so this may be bad since many slow web pages are slow because of the use of Flash.