My guess is that prices will remain low even after MoP is released. The gold is already in the market. Buying things from the AH doesn't remove a significant amount of gold from the market through AH fees. So unless someone spends it at a vendor the gold is still out there.
There will be more demand, but I wouldn't expect the gold prices to rise that significantly. Not to mention with the number of dupes and such that have been in the wild lately I wouldn't be surprised if there are some very large gold stockpiles out there. Unless you can work enmasse I don't think the profits are there for individuals.