We have and we felt we had to especially as we are travelling with our young son. We had a wonderful trip planned for Xmas/ New Year (staying at Trisara, MO Chiang Mai and Peninsula Bkk) and we have cancelled it all, rearranged to visit Siem Reap, Langkawi and Bali instead.
Although I think it likely that by December matters might well have settled down in Thailand, there is the possibility of elections later this year and the general consensus is that Thailand is increasingly unstable politically. So we felt it was too risky, as we needed to sort out an alternative now, not leave it 'til Nov when the luxury options would in all likelihood be booked out and we would forfeit deposits.
Other travellers will take an opposing view and if I were single or just travelling as a young couple then we might have decided differently. However, for us as a family, I believe it was the right choice.