I dont think you'll have any trouble with the GSM phones for quite some time. Reception might be spotty in some rural areas where there was very good analog coverage.
My dad was bummed when they turned off the tdma network. We were using an old at&t tdma phone with some goofball phone provider that allowed you to do something nutty like pay $8 for 20 minutes of time that were good for a year. Kept it in his glove compartment "just in case".
Be fearful when others are greedy, and greedy when others are fearful. Just another form of "buy low, sell high" for those who have trouble with things. This rule is not universal. Do not buy a 1973 Pinto because everyone else is afraid of it.