I'm using Ubuntu 14.10 dev (x86_64) with steam 1:1.0.0.48-1ubuntu1. On my system lxterminal is installed (which satisfy x-terminal-emulator) and one dependency of steam is "xterm | x-terminal-emulator". The problem is that steam seems to be only available as i386 which causes my installed lxterminal:amd64 to not satisfy x-terminal-emulator so apt tries to install xterm on my system. But interestingly apt gives xterm:amd64 a higher priority than xterm:i386 and it also seems that the architecture of the terminal isn't important here. In this case the dependecies could propably be updated to for example "xterm | x-terminal-emulator | x-terminal-emulator:amd64". This would have the advantage that users on 64 bit systems with 64 bit terminals other than xterm doesn't need to install xterm for steam.