Lol...First off, like someone said earlier...We will not see a US SG3 version anytime soon. If I had to guess I'd say maybe we'll see it by the end of Summer/ beginning of fall here in the states.
The Skyrocket HD would be the perfect device to release with ICS at this very moment. Number one it would phase out the previous two SG2 devices that launched on at&t, as well as provide a real alternative to the Note which is just too big for most people.
And number two this would also provide a nice cushion until the One X launches on at&t, which has been said to not be hitting the states until the late Spring/early Summer months.
My timetable guess would look like this.
Skyrocket HD with ICS- March 2012
HTC One X- June 2012
SG3- September 2012