Xbox 360 was an ok name but i wish they had kept the project code name "Xenon". So I kinda hope they use that as the name for the next Xbox machine but I doubt they will.
my friend knows a guy who once shared a room with a guy who has it on low authority that it will be called the 720 out in 2020
I doubt Microsoft will wait that long to release a new Xbox. I don't know anything about it, but it seems like most new consoles come out about 3-5 years after the original. Sometimes less sometimes more.