I think it'll be nice to have a fresh start!
It would be painful to have a new start for those people that have built massive buildings or that started a long time ago. I don't think it's the best option to take since, like how Rich said, there is plenty of undiscovered areas around the world... If you want a new fresh start with the new 1.7 biomes, I would recommend to try to discover those lands through dynmap when we update the server =]
Well, by a fresh start, I also would like to see everything started again, not just the map.
People racing trying to be on the top, by mcstats and cash lol.
Yeah you would need to let go of stuff, but you can build it bigger, and better!