There's no way Orlando is anything but the 4 seed and there's no way the Knicks get to the 5 seed, so Orlando's out. Chicago has a 2 and 2.5 game lead over Boston and Miami and the Knicks have a 3.5 game lead on Indy. These teams have 6-8 games left in the season so it's pretty unlikely that Chicago or NY falls, so it's probably not Chicago. That leaves Boston and Miami.
Boston has a 0.5 game lead on Miami with 8 games left and Miami has 7 games left. The 2 seed in all likelihood comes down who wins on 4/10 when they play each other. My guess is that Boston wins and it's NY-Bos in the first round. Not a great match-up, I'd much rather see Chicago or Miami since the Knicks have shown they can beat them.
EDIT:
I'm looking at Miami's and Boston's schedules and it's a bit more complicated then what I said.
Miami has 7 games against Minn, NJ, Milw, Char, Bos, Atl, and Tor. Boston has 8 games against Atl, Det, Philly, Chi, Wash twice, Mia, and they end the season at home versus NY. It's very possible that NY-Bos game could decide each team's first round opponent. If NY wins they could end up playing Miami, who they match-up better with, and Boston could play Philly. If Boston wins they would probably play NY and, probably more important to them, would have home-court advantage in a probably second round match-up against Miami. It will be an interesting two weeks.
Now the joy of my world is in Zion
How beautiful if nothing more
Than to wait at Zion's door
I've never been in love like this before
Now let me pray to keep you from
The perils that will surely come