The scary thing about this is: Stuxnet is one of the "most sophisticated" pieces of malware we have discovered up until now . Who knows what kinds of software are still out there quietly doing their thing in the shadows.
We're quickly heading toward the age of the first Virtual WMD. The implications can be as wide as your imagination, but possibly worse than existing WMDs.
I know hackers hate the word cyber because grandma uses it, but it's the right word for it. The stand-in "computer based" almost works, but it doesn't cover things like hacking radios.