I'm wondering how serious you are about this. You really can't think of a single scenario where it hasn't?
Moore's law shutting down tomorrow, the whole Western world going into a Japan-style Lost Decade, an asteroid strike in the Pacific causing a tsunami wiping out the West Coast, Japan, Korea, and part of China - or just the Big One hitting California* - a demographic apocalypse choking off all major investment, a limited biotech/nanotech plague, limited nuclear exchanges (touched off by Russian adventurism into Georgia, North Korea, Iran...) etc...
Heck, I'm not even trying here. There are tons of scenarios in which no Singularity of any kind has hit by 2040. (Good quip, though.)
* do you live in those areas and expect to not survive any major disaster? then rewrite them to take out the East Coast, England, etc.