There's a Mass Effect iPad app called Datapad and apparently u get messages on it from squadmates as u progress through the game. Some people are reporting getting this message AFTER the Ending:
Also, apparently Mass Effect's Twitter account has been dropping hints like crazy...
User 1: "I still want to believe you guys are sneaky trolls and have something going on you don't tell us yet. Can I get a cryptic reply?"
@masseffect: "The sun, it shines. www.youtube.com/watch"
User 2: "You are either a massive sadist or a beacon of hope."
@masseffect: "Can't it be both?"
User 3: "I kinda feel lost after that ending...not what I expected and left me feeling everything done was for nothing."
@masseffect: "We know it's a lot to take in! But hang in there. Your decisions matter."
User 4: "Are you holding something back, that could quell the large amount of frustration from the community, a tiny hint would be enough."
@masseffect: "Mike Gamble already said on his twitter, if the fans knew what was in store, the reaction would be different."
User 5: "I loved 98% of ME3..but something has to be up w/ ending..too much talent at BW for that business. Keep my saves?"
@masseffect: "We're keeping our saves, that's for sure."