I'm writing a SF book on this very idea (severly exaggerated of course)
The main group of people would dwelve into exaggerated PC-ness,to the point that a city has thousands of different architectural styles in the same neighbourhood and everyone woudl speak a different language depending or origins, social retardedness to the point where we stop talking altogether to communicate through e-mails and SMSs, God would be on the same level as Santa (if lower) , we would celebrate stupid shit like International Kidney day instead of Easter and Pick your Nose day instead of Christmas, some people would be lethargic, sad individuals with no will to live or morals (since they don't fear burning in Hell) and well, it'd be better scientifically, but not morally.
All sexual deviances are allowed, AIDS and syphilis would spead like wildfire, and many bastard children would get aborted every day.
On the other hand, all religious people would isolate themselves in their own community sorta like the Amish, fearing science would corrupt their youth,and be very selfish and backwards people.