On my radar for the next 3-6 months is the increasing cost of food. As the middle classes grow in BRIC countries they will want their share of the food and much more than before. This will have an upward pressure on food prices. This could potentially cause US incomes to drop significantly as a larger proportion of US and European wages are spent on food costs, leaving less around for the discretionary purchases.
Bear in mind though the US wastes a lot of food, so the increasing costs may just cut out the wastage and make people a little slimmer, reducing the economic burden of fat people on the western economies. This will save the US around $117bn a year.