While I won't dispute that a block heater makes starting the engine easier, consider this article:
http://www.gi.alaska.edu/ScienceForum/ASF7/747.html
How many people can actually say their cars wore out from cold weather starts? As opposed to wearing out from something else...
It would be interesting to drain some oil from a car that was left plugged in overnight on a -25 Calgary night - I wonder if the oil really would be that much lower viscosity considering a block heater is only about 400 watts at most.
Someone else can try though - I'll plug mine in for the time being.
