No. Apple follows Intel's roadmap, any update there could be is about a year away.
Open it! You have 14 days from the date of purchase to return it for a full refund or exchange, so you have nothing to lose if you open it now. If you wait till Thursday, and there is no new rMBP (which I highly doubt there will be) then you would have just wasted 3 days, where you could have been enjoying your new rMBP.