I think some time in the next 3 years they'll win one more. Danny has locked up this core of players for 3 years (except PP and I have little doubt he'll be with the team the following year) so we have a very good run ahead of us with NBA-caliber players. If Sully and Melo develop, even better. add in that Danny will be able to add MLE talent each year to what we already have and I can only see things getting better (barring injury)
I think a sense of desperation will set in with PP and KG if they don't win this year -- they'll make an all out push to win one again before they retire.