Low oil is probably great for most economies and global growth in general. Although it might suck for economies dependent on oil (hopefully this pushes diversification on Canada's economy a bit more)
Speculation is that this is an attempt on Saudi Arabia's part to get new American shale producers to go bankrupt.So that might happen and prices will go back up, or perhaps the US government will bail out these shale oil producers, essentially subsidizing super cheap oil prices for a while.
EDIT: Actually, even if some oil companies do go bankrupt, someone else will just buy up the wells and work them instead.
Speculation is that this is an attempt on Saudi Arabia's part to get new American shale producers to go bankrupt.
EDIT: Actually, even if some oil companies do go bankrupt, someone else will just buy up the wells and work them instead.