I do not know. I wonder the same thing. My friend just ordered the 2232, so we will find out I guess. From everything I have read, they are the same. In fact, the specs for the 3232 are slightly off. It is capable of 20 fps at 3MP. All of the specs state 15.
I think I found the difference. I just got dropshipped 5 2232's directly from Hikvision USA, They have no mounting holes on the back or bottom. The only mounting option is the one attached to it. I've attached some pictures of my Cams. Heres a 3232 I found on ebay that has back and side pictures which the mounting holes. I am a bit disappointed that they don't have the holes.
http://www.ebay.com/itm/Hikvision-DS-2CD3232-I5-IP66-3MP-EXIR-HD-1080P-IR-Network-CCTV-IP-Camera-POE-/151364039265?pt=US_Security_Cameras&hash=item233dfff261
Ebay Link to camera with mounting holes.
Pics of 2232 I took this morning at work.
http://imgur.com/a/8Dk8k