"Wouldn't it make more sense to temporarily decrease the rent rather than, add utilities, lose the tenant and possibly miss out on rent?"
David, if the previous landlord was paying the utilities you can bet they were being used and abused to the max. You will find that the rate of usage will dramatically reduce when the tenants start to pay their own bill. This alone will take some of the shock out of it. Stop thinking about a rent reduction. Just give plenty of notice that the utilities will become the responsibility of the tenant. Make it sound like you are doing this instead of a rent increase.