Am I obligated to pay utilities for a home where I no longer live?

You need to file any court orders. If your name is on the lease and there is no court order you do not have to leave the house.. If your wife wants you to leave, give her conditions on what you will agree pay if you leave. If she does not agree stay. If she agrees put it in writing and file it with a court as part of a status quo order until your divorce is final. If you do not know how to do this hire an attorney.

Unless ordered to do so by the court, the rent and utilities are not your responsibility but are the responsibility of the party living there.

Since you will pay support and they are living in the residence, the support should be sufficient to cover her expenses. You do not pay additional costs.

Your obligations, during the pendency of the divorce, will be determined by the court. If you are assessed child support and spousal support temporarily it is doubtful that the court will also make you continue to pay the utilities at the residence you no longer reside in. Clearly you need to see an attorney.

If she's getting spousal support, she should be paying her own utilities. However, until there's an order, you should probably pay them and ask for credit towards support. If you are on the lease and she doesn't pay, you could be at risk for damaging your credit unless the landlord agrees to take you off the lease and put her on it. You should probably meet with an attorney, figure out how much support would be and enter into a stipulation regarding paying temporary support so that you are making payments and getting credit.