While nobody is perfect it's hard to argue that Mayor Bloomberg hasn't been a net positive to New York City. However I feel strongly that it's a bad idea to change term limits with a vote of the city council. This is the sort of issue that's so big that it needs to be voted on directly by the public if they feel that term limits are a bad idea.
Here in Williamsburg our council member opposes term limits and this is my email to Diana Reyna, District 34 - Council Member - Democrat:
Dear Council Member Reyna,
I strongly urge you change your position on term limits. Even if he's a good mayor, what Michael Bloomberg is proposing is not in the best long term interests of New York City. This city has a well known history of corruption dating back to the 1800s and while terms limits alone won't solve this problem it's a step in the right direction. It's not like this city isn't a lacking for a large pool of talented people that can be drawn upon to serve in government. Even if you disagree with me I'd ask that you not vote on the issue behind closed doors and allow the public to directly vote on this issue in a referendum.
I'd urge everyone who lives in New York City to write your representative on this issue.