E-Miles Customer Service response
I sent e-miles a note asking about airline (and other) redemption options once Delta goes away. The response I got, although not exactly crystal clear, may provide some indication of where things go next:
"Thank you for contacting e-Miles® Member Services. To clarify, e-Miles is the unique partner program that lets you earn free miles toward your frequent flyer account. Currently, our sponsors include United Airlines®, Hilton HHonors®, Intercontinental Hotel®, AirTran Airlines®, Frontier Airlines®, Alaska Airlines®, Amazon®, Southwest Airlines®, and US Airways®.
You will also have access to dining, other retail, and other travel sponsors of e-Miles. Please click the link provided below in the e-Miles Announcement Email sent on 12/21/2012."
As someone who was locked in to Delta from a decades-old invitation, I actually welcome this change if it allows me to redeem for United miles.
Of course, the skeptics among us will notice the CSR's use of the word "currently" when discussing the program partners....