General Comments
 

When will American and United join the program? I like Diners but like Am Ex better but i also am a big flyer on American. Any chance that will happen soon, I've been waiting for years.

It may be that they've joined already, albeit by the back door. Neither American or United are official partners with Membership rewards, and sources at AMEX tell us that no direct partnerships are in the works. But since Delta and US Airways are MR partners, it may be that MR members may soon be able to earn and redeem awards on American and United. But the key word here is MAY; nothing is definite about the alliances between Delta and United and American and US Airways, concerning their frequent flyer programs. Literally anything seems possible at this point: it could be that the new alliances will come with drastic restrictions that freeze redemption options at something very close to present availability, or it could be that a vast array of new options will be opened up for the creative frequent flyer. Rest assured, we'll be watching developments closely, but for now it's really a matter of wait-and-see.