If you could merge all of the search engines into one monster engine with the best algorithm ever, what engine would it most resemble, what concepts from each engine would you employ, and what would be your best spam fighting technique?
I would personally keep hilltop, hubs & authorities, and toss most of the rest. Link popularity has got to either go or be re-invented. The results I would want to resemble Google's only in look and feel. I'd of course want them to have less spam and list my own sites higher :-)
The final thing I'd do is have different topic grouping show from an initial search. In a search for Eagles, I'd have the musical group, animals, sports teams, etc. showing, then make the user show intent by narrowing the results. Of course, some default results would be shown, but only below those top level narrowing links.
Now, what would you do?