Now is a great time to start looking into your upgrade and looking into some of the advantages (and disadvantages) of each potential Galaxy Note 5 carrier.
The Galaxy Note 5 is confirmed for AT&T and Verizon and it should also be coming to Sprint, T-Mobile and U.S. Cellular. The Galaxy Note series has never come to smaller U.S. carriers so you'll want to prepare as if the Galaxy Note 5 will be stuck with those five.
If you're a free agent, you'll want to investigate a few things in particular. Take a look at the network size of these carriers and gather feedback from users in areas that you frequent the most. The last thing you want is to go to a carrier with terrible service where you live or work.
You'll also want to take a look at reports about customer service. Some carriers are better at this than others. All of these things are important and you're not going to be able to get a clear picture if you start your research a day, or even a week, before the Galaxy Note 5 release. Get started now.