It used to be the more gears you had, the better. Now it seems evolution is going in the other directions, with less gears the way forward. 2x10 has become very popular over the past couple of years, but some people have taken things a step further, going 1x10.
The new wider range cassettes has helped make this possible, along with people realising they probably didn't need all those gears anyway. SRAM has recognised the popularity of 1x10 and gone a step further with their new groupset.
SRAM has released only a few details about XX1, preferring instead to wait until July to give us the full fat press release. For now we'll only know the following:
New 1X MTB drivetrain
Designed for Enduro and XC racing
Innovative chain management technology including TYPE 2
Grip Shift and trigger shifter
Widest range cassette available
Will it be 10-speed? Or 11?
What it doesn't state is whether the new groupset will be 1x10, or something else. The safest prediction is that it will be 1x10. But the line about the "widest range cassette available" suggests that perhaps they're ready to launch an 11-speed setup.
But given we've not yet seen any 11-speed offerings in the mountain bike world, and SRAM haven't even gone down that route on their road groupsets, it would be a brave step indeed.
So now you know as much as us. More details soon.