At the risk of turning this into a sports thread, I think it's pretty obvious why they would move to Brooklyn: exposure. Even in the years when the Nets reached the finals, they had trouble selling out the Meadowlands/Brendan Byrne/Continental Airlines arena/the Izod Center (lots of name changes!). The place is like a graveyard for many regular season games. Even if they will still be in the shadow of the Knicks playing in Brooklyn, it's hard to imagine them not getting a big spike in attendance and national visibility playing in the #1 market in the country, rather than in the shadow of the #1 market in the country and all the way out in the swamp.
I don't think there would be a change in their coverage unless their contract runs out around that time. However, being on WFAN right now, I'm sure they're quite happy with the coverage they are getting, as they are on a station with a much better signal than WEPN, which carries the Knicks.
That said, it would have been nice to see the Nets stay in NJ and play at the Prudential Center, but such is business. However, if the Knicks continue to really, really stink for a few more years, I can see the Brooklyn Nets stealing a lot of the Knicks' thunder, and new fans.