weird, I emailed REI a week or so ago about the xtherm and got the following reply:
"Thank you for the email response.
We don't know the exact date for sure. You can check back on the website early April. The 20% coupon is good through April 10, 2012.
If you purchase a different pad with the coupon, you can also exchange it for the REI Therm-a-Rest xTherm pad when it comes in and we will still honor the 20% off coupon.
Please let us know if we can be of further assistance."