Kate,
Considering that days on market in a normal real estate environment averages 180, two years is a relatively short time to buy something then move again. You might be able to get a seller to pay closing costs, but when you sell you need to factor in the expenses of the sale- conveyance tax, real estate commission, attorney's fees. If you are looking at a small mortgage, likewise the tax benefits for payment of interest on the loan will be smaller as well. Talk to your accountant or visit http://www.irs.gov/
for information and review your financial situation to see i what would be the tax consequences/benefits.
You don't say if you have any pets. As a renter you may pay a premium for renting with pets.
If you can find a distress situation where a seller has to sell (say a short sale , foreclosure or estate) and you have the financial wherewithal and patience to wait for an answer, you may break even or possibly come out ahead in two years.
Each person's situation is unique, so what may "make sense" for one, may not for another.
If you are not currently represented by a Realtor, feel free to contact me-
All the best,
Margaret Shea

As both a homeowner and a lawyer, I wouldn't recommend that you buy a home for just 2 years. If you add up the closing costs for a buy and a sell, plus homeowner's insurance, taxes (they're high) and no guarantee that there will be much appreciation, you're better off renting. Rentals are fairly reasonable and you'll have your choice of neighborhoods.

It's hard to manage a rental from a distance and is not recommended.