Now is the time for you to evaluate what services you use most frequently and take into consideration the amount of money you spend on each. You can gather this information from your past shipping history. With the new pricing structures it may be to your advantage to switch carriers. Be careful though, services between the carriers provide different delivery schedules and restrictions. Make sure you are comparing apples-to-apples and your customers will get the delivery service they expect.
The end of January also marks the end of DHL's United States domestic delivery operations. But don't despair; DHL is still servicing the international delivery arena. So, if you do a substantial volume of international shipping, you should also check out DHL's rates and services.