Brilliant move by Google
Alongside the "we just want to help people get results quicker" angle, there is a subtler motivation for Google.
I am pretty sure that more people enter search terms from the General to the Specific than vice versa: people enter "Kitchen Worktops in Coventry" more than they enter "Coventry Kitchen Worktops".
By serving results before the customer has finished typing, Google are encouraging more people to act on a broad search term rather than a specific one.
That hands a gift to national/international operators whose sites make onto the front page of broad-term results an organic basis. So far, that’s not worth anything to Google. But everyone else will find themselves competing for Sponsored Links using the same few broad search terms, which will result in the auction price zooming up. That does make a difference to Google.
It will make life more expensive for mid-scale operators, who will end up spending more on Google if they want to keep their traffic flowing. But it might have even bigger impact on smaller players.
A small hotel in Coventry might have featured well on “Hotel in Coventry” – or might have been able to afford to buy a Sponsored Link for “Hotel in Coventry”. But with Google Instant, they will see a proportion of those searchers being tempted away by the listings that appear as soon as they have typed “Hotel”.
That small hotel will not have a hope of a front-page organic listing for “Hotel”. Nor will they have a hope of affording to bid for a Sponsored Link for “Hotel” (their click-through rate would be so much lower than a chain that their bid would have to be astronomical).
So, forget the disintermediation that we were told would be the result of the web. Google Instant is just one small step along the road which is forcing that small hotel to pay to appear on an aggregator site which can compete on a national/international scale.
(I don't live in Coventry, or run a hotel, by the way).