Xbox360Rally's Mill'o'rumor is abuzz with the following rumor:

Earlier this week, when news finally broke of the Xbox 360 Elite, making it official, I was quick to call my local Gamestop and ask if they were taking pre-orders. They said no. Fine. Two days later, I called back, and again they said no. Finally I called the Gamestop at my local mall (Genessee Valley FTW) and asked him if they were taking pre-orders. Again, he said no. But then something odd happened. He asked me if I owned an Xbox 360. I said yes, and he told me that I shouldn’t trade it in just yet. I asked why, and naturally he said he couldn’t tell me yet, but just to know that if I had plans to trade my 360 for store credit towards a 360 Elite (which was my plan, I admit) to hold off because “something big” is in the works for existing 360 owners.

Even more a quote from the Xbox Forums:

I called Gamestop today to see what kind of value I would get for my Prem 360 and the manager told me that they would have to see it in person, of course we all know that, but after talking to him about the elite he said that corporate had sent a memo stating that MS was working on a special Trade in for existing 360 owners to get the Elite. Im guessing there is alot of truth to the statement due to all the negative feedback from the gaming community.
That would make things alot better if they did.

All I can say is that even if it isn't true we should continue to spread it around just so Microsoft has to make it true ;)  Grumpy/Heartbreak ... I wonder if you can trade in broken ones?