Upload & Sell: Off
If you can wait six months or more then you might have the option of a Mac Pro with 6 Gbps SATA and thunderbolt - or there might be no Mac Pro at all.
Also, you might have the option of a 15 MBPr with retina display in the old case so that you can have an in-built DVD and use plug-in RAM and standard drives, more USB 3 ports, etc.. That's what I'm waiting for because neither of the current 15" MBPs suit me.
Either way, unless you have a pressing need to upgrade now you may well be better off by waiting. I know that is always the case but these things are too expensive to be buying something that is no better than nearly right. It would be very different if you were buying a cheap Toshiba at end of model runout sales because you afford to get one of them every year.