First off, Antoine Walker's a funny man, "What about slowing us down?" That was after game one. C'mon dude, watching your teams halfcourt offense is like watching water freeze. 
Gameplay: Both of these teams are perimeter teams, but couldn't be more contrasting in style. Jersey likes to push the pace and play in transition, while Boston plays a halfcourt set based on iso's for Pierce and Walker. However, expect this to be a real track meet, as NJ slows down for no one. They'll run off rebounds, made shots, turnovers, practically anytime they get possession you can expect them to push the ball upcourt. As for Boston, you can expect their players to hoist up any three as long as their able to see the basket. It's what got them here, and I don't expect them to stop. I really don't expect this game to be played at Boston's pace, because New Jersey's able to run on anyone.
Keys to Victory: 
New Jersey - Push the pace, of course. Run, and keep on running because Boston doesn't have the stamina to keep up. In the halfcourt set, try to get Kerry Kittles involved, and run pick and rolls or pick and fade for Kidd to keep the ball in his hands as much as possible. As for defensee Pressure Pierce as much as possible, d'ing him up close enough so that he has to turn his back to protect the ball. NJ could also try blind traps on him, because if you force Paul Pierce to go quicker than he likes, he's liable to turn the ball over. Also, try to deny his penetration as much as possible, and let him take jump shots. Let him be busy and not the rest of his team. As for defending Walker, I think Martin's quick enough to handle him on the perimeter and strong enough to guard his post game. Walker's in blind love with the 3-point shot anyway. 
Boston - Try to keep NJ from running, 
Key Matchup - Walker vs. Martin, I think Martin's gonna be able to take this one. He's able to post Walker up, and even with less-than-average outside shot, he should be able to catch Walker quick drives to the basket. Also, he should pick up a few easy points off putbacks. Defensively, as mentioned before, he's athletic enough to guard Walker anywhere.                                                                                                                                    

Sleeper(s): Kerry Kittles for NJ and Eric Williams for Boston. Kittles has always been a good shooter, and if he's able to get going, he'll make NJ's job a lot easier. Kidd should be able to get him going with transition buckets, and hopefully for NJ that'll spark Kittles' outside shot. As for Eric Williams, he's outmatched athletically outmatched, but I think he's physical enough to pick up points against Jefferson and Kittles. Look for him to turn and face on semi-posts and take the ball to the basket. 
Also, look for Lucious Harris and J.R. Bremer. Both of them are excellent three-point shooters, but very streaky.   If Boston doesn't try to slow down the game, look for them to get tired real quickly. Although they're a team loaded with swingmen and guards, it's still much too fast a pace to try to play after running a halfcourt game the whole season.  

Prediction: NJ in 5