Most places if you have two services then you will pay two monthy fees to the utility regardless of how much electricity you use. It is cheeper, over time, to only have the one utility bill.
As to your question about if you will need to replace the wire to the pole: You need to call your utity company. Most places, they own and maintain this wire. It depends on thier charter.
Edit to add: Your local building dept, or any local electrical contractor would also be able to answer this question.