I've had my Xbox 360 Elite 120GB model since Halo 3 came out in 2007 (IIRC) and it is still kicking.
The faceplate is cracked and the disc tray has to be coaxed out but it still works fine. I have Xbox Live Free because I have no desire to be insulted by 8 year olds.
I don't need 8 year olds telling me that they #%#%#@*& my mom #@%*#@&%#* Grandmother #$*#@&%#(*$#&(%* IDIOT! #($*@&%(#57 Camper @#%#$(#&
My Xbox does just fine right now. Unless the 720 includes FULL backwards compatibility with the 360 and includes hard drive content transfer, I don't think I'll get it.
Plus, the cool online games are for PC anyway. I prefer singleplayer console games and that generation is dying.