I'm pretty sure Deep Blue hasn't been released yet since it seems to be on pre-order on Saks and NM, with the bag shipping out in late October. Maybe it's a new color for Winter '12?
I'd gueeeess it was maybe similar to the color "Ocean" (not to be confused with Oceania!) from a past season which has been revealed here and is a beautiful dark blue:
My first Chloé -- the Paraty in Ocean
Another newby to Chloe (reveal)
All about Paraty
The Deep Blue pics on NM/Saks look pretty similar to that or maybe like a pebbled version of Ink Blue. I bet it'll be gorgeous!!
You can also try emailing Chloe to see if they can tell you anything about it!
HTH!