I guess you answered your own question. "Good" is a relative term. These players are "good" compared to the rest of the knicks roster, but not necessarily the rest of the league. I've cooled on nate and lee because of lack of development in their games. While I think Harrington has developed into something very worthwhile for any team.
Unfortunately i believe that N8 is just here to sell jerseys and tickets and pump up the crowd. He's not really an option to lead the offense and thus limited as a pg, he's not tall enough to guard SG's and so where does that leave him? Exactly where he is; Burried on our bench BEHIND duhon. I am still happy that we signed N8. He does still bring the energy to the game and has his moments. Plus he's the reigning dunk champion. Maybe poking at lebron's competitive edge will draw him to NY where we would LOVE to have him come and dethrone nate as the dunk champ.
Lee is actually a really good second option for a lot of teams at the 4 and in a pinch, or when teams want to go small, at the 5. I could see as we draw closer to the trade deadline playoff bound teams looking to beef up their bench with a player like Lee. That offers us a good chance to package him with JJ or Curry and make more room for 2 max FA's in the off season.
While overall I enjoy watching these players play, I do not think that they fit into the 2010 plan very well and I do not expect to see them back here next season (without taking MAJOR pay cuts). Its not that I don't like these guys, but I think I'll be happier when they move on to other teams and we make more headway into the 2010 market. They are "Good" in relative terms in certain roles and may flourish with another team. they are not helping the Knicks all that much right now however.