It should represent the current registration percentages of R vs D.
See here for instance:
Of all the polls you have seen, there is one poll that has gotten no attention, it is a poll that has been taken monthly, it is a poll that Doug Ross spotted and promoted on his site. It is the Rasmussen Poll of party identification.
They have party identification results online dating back to 2004. Here are the 2012 numbers through August
That shows a GOP advantage in registration this year.