I think it it truly impressive to see how far Newark has come in just the past decade, and it will keep getting better. There are many great improvements going on that I believe will really make EWR world class.
First, as said before, is the train station which is really taking shape. The quick train ride to Manhattan will give EWR a big boost, but also the station is on the busiest passenger rail line in the U.S., the Northeast Corridor. The airport will have accessibility from all over the Northeast that JFK won't be able to match.
Also, Continental's new concourse will alieviate the gate shortage problem as well as make a lot more room at the current customs facility, which itself is brand new. What many people don't know is that EWR is a significant connection point between the Star-Alliance partners, with a large presence of United, Air Canada, Lufthansa, and SAS. These airlines have been talking about using the freed space at the customs facility to enhance connections there.
For those complaining about Terminals A and B, they too will be improved. The Port Authority has signed a deal with B.A.A., who operates airports in the U.K., for renovations and new retail stores. Also, the new parking garages will add many much-needed extra spaces, and there are several road improvements in progress to make it easier for drivers.
The one thing that is causing problems for Newark is the infamous delays. These problems are correctable through better scheduling and a redesign of the NY area's airspace, however, several business and bureaucratic issues have been holding this back. There is a new control tower coming, which hopefully will be better able to handle Newark's traffic.