This is a bad example. The floppy disk icon means "save" and has now for very nearly as long as floppy disk were in common use. It's the same as a "tape" icon means something to do with video even though video cassettes were only a common thing for 10 years.
The Apple II was the first computer that was widespread enough for people to have seen that had a floppy disk. It came out in 1977. Apple dropped the floppy disk in 1998 (21 years later), so it's been 22 years since it was standard in Macs.
Even allowing for some switching time, it has meant "save" for longer than it was a common physical object.
Awesome question. Replacing it would be worse of course (because then not even the old timers understand it). One thing i liked about google docs?? Was automatic save, maybe this is the trend. If you take a 5mb picture on your smartphone there is no question do you want to save it. Space is cheap.
But if i really have to come up with something, I'd say green arrow pointing up. Meaning 'upload to your (own private) cloud'
