This year, while sending in their predictions for the regular season, several people took a shot at making playoff predictions for the Good Guys as well.  So, here they are.  Remember, these were sent in before the regular season even started, and not everybody chose to speculate on the potential playoff picture.  Back then, the team was different, so be nice.  Also, the NBA changed the opening round format from 5 games to 7 late in the season.

They Will Make the Playoffs
Jonathan Branin (predicted "Make playoffs.  Lose to NJ in whatever round we meet them.")
Kim Malo
Dorine Pratt
Jeremy Ryan (predicted "4th place in the Eastern Conference")
Steve (predicted "just getting the seventh seed away from Atalnta.")

How they did: Jonathan, Kim and Dorine are ok so far, since as of April 9, the C's did indeed make the playoffs.  Jeremy gets half credit as the C's dropped from 4th to 6th over the last few weeks of the season, and Steve is way off regarding the Hawks and underestimated the seeding.  Sorry, Steve.  Jonathan proved unfortunately accurate.
 

They Will Make the Second Round of Playoffs
Roy Enrile
Jim McMaster (predicted "bottom half of the playoffs, out in second round")

How they did: Roy was right as far as he went, and Jim McMaster, sad to say, was also right.
 
 

They Will Make the Eastern Conference Finals
Mafiaso316 (predicted the C's lose in 5)
pdbauer
Issac Robbins

How they did:  New Jersey put an end to the C's playoff run in the second round.
 

They Will Make the NBA Finals
Ellie Cutler (predicted "Eastern Conf. champs, lose to Sacramento in NBA finals")
Josh Ozersky
Patrick Goggin (predicted "3 seed in east, beat NJ in ECF, lose to Kings in 6")
Warwick (predicted the following: Playoff time - Walker steps up and wins Finals MVP as the losing teams hero as the Celtics go down 4 games to 2 in the fleet center to the Sacramento Kings. The basketball world will remember the NBA Finals for Antoine Walker's heroics in a brave game 5 as he leads the Celtics from 12 points down with 6 minutes left to force OT and then scoring 7 straight points in the OT period.)

How they did:  New Jersey put an end to the C's playoff run in the second round.

They Will Win it All
Banner  17 (predicted "All the way to the Finals.  4-3 over the Kings.")
Snoopy the Celtics Beagle

How they did:  New Jersey put an end to the C's playoff run in the second round.
 

So, who "won"?

Jonathan Branin and Jim McMaster.  Jonathan predicted a loss to New Jersey in whatever round the meeting took place, and Jim predicted the C's would lose in the second round.