I was in the same boat trying to decide between buying the '11 or waiting to see if the '12 SESG was going to be offered.
You're going to have to ask yourself some questions:
Is there anything (like color, etc) in the '12s that you REALLY like?
Is there anything (like color, etc) in the '12s that you REALLY hate?
Are any of the '12s "speaking" to you?
If the answer to any of those is YES then I would say you should SERIOUSLY consider buying the '12 before the '13s come out.
Reason being is that as the models are sold off later in the model year, they get harder to find so that if you like a certain color over the others then you may not be able to find it available - even worse if you HATE a color and wait, you might get stuck with that one...
What it came down to for me was that I loved the kryptonite and it started to speak to me - I ended up pulling the trigger and have NO regrets at all.
The saddle bag speakers and light up CVO console medallion that I missed out on are nice but just not worth it for me when comparing the color of my Goblin with the colors of the '12s.
NOTE: Please don't take that as me putting down any of the '12 colors - I'm not saying that they suck, I'm just saying I prefer mine.
In the end remember one thing - love what you buy and make it your own!
GOODLUCK!!!