Nah, I don't believe that for a second. It would be the first time in history (I think) any consumer electronic device could not be sold / traded / given away once it's been used.
Besides, DRM might be legal (albeit immoral) but I'm pretty sure it would be illegal to prevent people from being able to sell hardware in most countries.
Unless Microsoft makes you sign a long term rental agreement where you accept that the rental contract on the Xbone is non-transferable once an XBL account has been activated on it then buying a Xbone means you can sell it to someone in full working condition.
Long term rental might be not all that bad, if they guarantee to replace a faulty Xbone at no cost for the length of the rental contract.
Also, perhaps if you buy a Xbone through a Cable subsidy arrangement perhaps you are not allowed to sell the Xbone for the minimum duration of the cable contract, which is not unreasonable.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
