JKR has updated her site today -- WEBSITE SPOILER!

[potioncat]

No: HPFGUIDX 158280

Snow: 
> 
> Oops one more last thought, promise
what if James allowed Dumbledore 
> to borrow his Cloak to hide the other intended victim?
> 
> Snow attributing many of these thoughts to listee's of days gone by


Potioncat:
This is too much! We've discussed James's IC many times and at great 
lengths yet it turns to be something no one ever asked herself, but 
should have!!!!!!!!!!!!!!!!!!!!!!!

So, we may have figured out the important matter and not know we did. 
Or there's something more to the IC's location that we never 
considered. Where's SSSusan? How about rethinking TURBAN? (TURBAN 
DREAMS---whatever it was, I just recall it involved lots of margaritas)

I can't think Snape or DD could have been involved with GH without 
knowing Sirius was not the SK---unless of course they were given the 
location on a piece of paper and thought it came from Sirius.

You know, JKR just tossed out something for us to worry over that we 
thought was long ago deemed unimportant.

Potioncat, who does not mean to imply by "we" that she actually came up 
with any original theory about the IC, but more likely was lurking 
about and reading about it. She was however, highly involved in turbans 
and margaritas.

Oh, those were the days, my friends...