Well - there's no such thing as a sure bet.
But Europe, North America, Austrailia and Japan are all seeing fertility rates that are at replacement levels, or lower, and have reached this point since the post war baby boom.
Since these areas more or less make up the developed world, I would say there's a pretty good chance.
Sorry - don't have time to look up references for the low fertility rates on this right now, but here's the wikipedia entry on the topic
http://en.wikipedia.org/wiki/Sub-replacement_fertilityInterestingly enough - Japan is mentioned.
"Another, perhaps simpler explanation, could be a reduction in the frequency of sex in populations with low birth rates. For example, according to a survey published by the Japanese Family Planning Association in March 2007, a record 39.7 per cent of Japanese citizens ages 16-49 had not had sex for more than a month "
