One argument against waiting is that Apple seems to be trending toward making it harder to replace internal components of its systems -- no replaceable RAM in the new Airs, hard to replace hard drive in the new iMacs, only Apple SSDs get trim support in the new MBPs without some effort, etc.
No one outside Apple knows if the 2012 models will continue that trend.
The 2012 MBP models could have two thunderbolt ports (no other ports, just some dongles), no optical bay, 8GB non-replaceable RAM, and a choice of 256 or 512GB SSD sticks from Apple. Or not.