It all has to do with your needs, your finances, and the possible rental income.
The first thing to consider is whether you absolutely have to sell. Judging from your question, you don't. You'd prefer to sell, but your future plans would work if you rented it out. Now, if you had to sell--positively, no question, had to sell--you wouldn't have a choice. You'd cut the price, possibly consider a short sale, anything to get rid of the property. But that's not you.
The next thing to consider is whether you can afford to sell. Example: You bought a house in 2007 for $500,000. Comps are now $400,000. You don't have the money to come to closing with over $100,000. You can't afford to sell conventionally. In that case, you might as well bite the bullet and rent it out. However, another scenario: You bought a house in 2003 for $365,000. Comps are now $400,000. You're priced at $399,000. In that case, it might make sense to keep it on the market.
The next thing to consider is potential rental income. How close will the rent come to covering your mortgage? Or might the rental income actually exceed the mortgage payment? In that case, it could make sense to rent it out, break even or get some positive cash flow, and wait until the market strengthens in order to sell. On the other hand, if you'd be bleeding $500, $700, or more a month on negative cash flow and wouldn't be able to afford that, then renting it out wouldn't be an attractive option.
Here's what you do: Ask your Realtor: "Where should I price the property in order to get offers? What will it take to get an acceptable offer in 60 days? Be honest." If you can live with that number, keep your property on the market. If not, then ask: "If I were to rent this property out, what could I expect in monthly income?" If that number is higher than your mortgage, or if the negative cash flow is something you could live with, then rent it out.
If you're living in the house now and don't absolutely have to move--and if you can't afford to sell it or rent it out--then stay where you are. If you absolutely have to move, but can't afford to sell or rent it, ask your Realtor for suggestions.
Hope that helps.