The subject of FPs for character greetings isn't important enough for me to bother spending a lot of time thinking or worrying about it. But I do want to comment on the worries that some people have that this is the first step toward establishing a reservation only ride system.
I'm not sure if the people who are concerned about this are worried that ALL rides will go to reservation only or that just the most popular attractions will be treated this way. Either way, though, the fears seem totally unfounded.
If a ride were to be treated as FP only for the whole day, that would mean that when the rope drops nobody would be allowed to walk right to the attraction and ride unless they had a FP. Just think for a second about how ridiculous this is. Based on our own experience and recent reports from Josh at easywdw and other posters on this board, if you walk directly to a ride like Thunder Mountan at rope drop you can ride multiple times with no wait and without a FP. If Disney were to adopt a FP only policy, that would mean that for a certain period of time, they would be operating rides at significantly less than 100% of capacity even though there are plenty of people in the park who would love to fill that capacity. The same thing would happen in the final hour or hours before closing when the capacity exceeds the demand. Depending on how crowded the park is, that could continue for several hours and, for many attractions, it would continue all day. No matter how sinister you think Disney is, you can't possibly think that is what they want to do.
A lot of posters on this board have said that they are unwilling to wait in a standby line of more than 20-30 minutes most of the time. If that is your attitude, a number of the most popular attractions in the parks are already de facto reservation only, and have been that way for years. Using TSMM as the most obvious example, the standby lines there are an hour or longer except at the very beginning and very end of the day. If Disney wants to eliminate my right to wait in a standby line that long, I really don't care because I have forfeited that right voluntarily. If Disney made Anna and Elsa FP only, would that really be a significant development for very many guests?
The absolutely worst case scenario I could see is that Disney would allocate 100% of ride capacity to FPs and the standby line would become a true standby that would be used only to fill gaps that might arise in the arrival of guests with FPs. There would be no guarantee that someone in the standby line would ever get to ride. I really don't see Disney doing that either, but it wouldn't really bother me if they did. I just don't think there are that many rides that would "sell out" of FPs, especially in the first and last few hours of the day, unless Disney significantly increased the number of FPs every guest can make in advance and/ or hold at one time.