Re: Goodbye Skype?
"Are there other binary-only proprietary things that folks might want to keep using in the Linux world?"
Yes. Chrome probably is the most popular example though Google offers a 64-bit version. Steam reportedly has 1500 games for Linux - of which most (all?) are prorietary.
Wikipedia: List of proprietary software for Linux
Some of those listed programs are obsolete but I personally have several clients running Oracle under Linux, even some old 32-bit 9i installations.