I am pondering whether to buy a brand new PD-170 or try and get a deal on a used PD-150 & VX2000. I figure it roughly works out to the same price and I would get another high quality camera for B roll at weddings.
What are the major differences between the PD150 & 170?

I would go with the new pd170 its a very good cam,

theirs a few changes to the 150 the main one been better in low light and a few otheir little tweek's, but you won't be dissapointed.

If weddings are a big part of your year then you'll certainly need two cameras to give you some editing freedom during the ceremony at least. I'd say that the 170 is the best camera, but the 2000+150 will make you better films at the end of the edit.

tom.