Bigger picture I think the arrival of ASICs will be like the Industrial Revolution (in the US) impacted farmers - lots of small farms closed down or were consolidated into bigger, more efficient farming corporations. There were (and are) still plenty of small farms around, but the majority were replaced by larger, for-profit businesses. Bitcoin mining will go the same way. Mining farms will invest and buy tons of ASICs, some enthusiasts will run a few jalapenos for old time's sake, but most will sell their GPUs and (hopefully) start using their coins to buy and sell things.
This argument makes no sense really since it does not take into account the increase in difficulty that will result from a significant raise in overall TH/s that ASIC rigs will produce.
Industrial revolution allowed more land to be farmed but it did not make it harder to get the same yield, in fact it was the opposite.
Bitcoin mining is a totally different ball game altogether. With the ability to have for less than $10K 270 to 420GH/s of power and very limited electricity consumption, GPU mining will quickly become obsolete (read not profitable). Unlike farming, there is no gain in small MH/s operation (such as organic farming for example). ASIC mining will just become the new norm since anything else will be not profitable.
That said, this will not happen overnight but I would think over the next 2 to 6 months. We shall see.
Heaters will probably give you more efficient conversion of power to heat compared to the cards, but it might be close. 
