Like Dave said, we'll have to see if this impacts balcony bookings. I haven't looked at other lines' policies in detail to see what they are, but I imagine that it's easy for cigarettes to get suck into the propulsion / engine systems if they're tossed overboard from the balcony.
Personally, I'm a non-smoker, so I think this is a good policy. However, I know some people do like to smoke, so they may not be happy about this policy.
I haven't tried Carnival yet, but would like to on an upcoming cruise. Just have to decide when and where. Thinking maybe the Eastern Caribbean next maybe in 2015 or 2016.
2007 - Majesty of the Seas (Bahamas)
2009 - Enchantment of the Seas (Western Caribbean)
2010 - Freedom of the Seas (Western Caribbean)
2013 - Golden Princess (Alaska, roundtrip from Seattle)