I think some people are speculating and hoping for a Apple 7 inch tablet. That is why there are so many users on the fence about the Nexus 7.
For those looking for tablets, there is at least one new Android tablet in the Galaxy Note 10.1, as well as a handful of Windows 8/RT tablets on the way, and as mentioned previously, the new Nook and Kindle tablets are speculated before the end of the year, too.
I can see where a decision would be hard to make at this time, as well. Granted, they won't all be in the $200 to $250 range, but some may (Apple possibly) be there, offering the consumer another choice to figure in.
All in all, if the OP wants to wait until Christmas, then that is their choice, as they may be able to make a more informed choice at that time amongst any tablets on the market.
I myself chose to buy a 16GB Nexus 7 now, as I like new gadgets. Four months from now, I could be looking for something new, too. Not that the Nexus 7 is not good enough, but a newer tablet may come out that better suits my needs on a daily basis for work and play (rear camera, SD Slot, handwriting recognition, etc.).