I have not heard about DTV making this offer available to current subscribers. It appears though that because of your out of date plan they are treating you like a new customer and extending the summer offer to you in order to get you to sign up for a new plan.

If you are not crazy about the NFL package, you can push next time they call for the winter offer which is 3 months of HBO, showtime and starz; HD DVR (with mail in rebate), $18 off per month for up to 12 months, and they just released 4 months free HD service.