Yes, I know that Google has provided SMS access to calendar but this is significantly different- especially for anyone with more than 1 calendar. That used to be my biggest peeve with SMS access - I couldn't see anything other than my main calendar. That meant I could never check my kids sport schedule.
The new mobile calendar app makes this one significant enhancement. I can make other calendars visible. Indeed it appears to use your web based calendar selections.
Well done Google! A great app takes Abother step forward.
To check out the app point your mobile browser to
http://www.google.com/calendar/m and enjoy!