That is a good question.
I think the main focus should not be on backlinks the amount you have should not matter. It would sure put the spammers out of work. Advertisements on sites would be worth more
I think it would be nice if the search were random. Meaning everyday different sites would end up on the ft page not the same sites.
Example do a search for fishing (First word that came to mind why I do not know.)
fishing - Google Search
Now tomorrow if your site was on the ft page it will not be their again till all the sites on dealing with the topic of fishing had been on the ft page
This would give everyone a chance and people would bookmark and save/revisit the sites they liked most.