[Ineti]

As for the 4e needs minis idea, I think minis or some form of counters (be it poker chips, coins, pieces of candy, whatever) and graph paper or hex paper is very useful for getting the details right (such as flanking, ranges, attacks of opportunity, etc.).

If you and your players can visualize all of that in your heads, then no, you probably don't need minis or maps or counters. For my and my group, though, we much prefer the visual effect of having color minis maps and 3D miniatures we can paint or customize to look like "our" characters and be able to move them into a position on the map that says "That's where we are in relation to the bad guys" and have no chance of misunderstanding take place.

My 4e GMing has shown me that using minis and maps is actually speeding up our gameplay. YMMV, of course.