I hate to say this, but I should say that the Japanese must end Pokemon anime, then the rest of the world follows. Since the anime is created from Japan, ending this anime maybe a impossible task. I felt offended because we cheated the young Pokemon fans that Ash started conquer us years ago. We watched Ash since childhood, teenage and adult years. And one day, your child watched Pokemon anime, telling him/her that Ash is new to him but for you, it is the old character from your childhood memories.
I forgot, that this question includes the future sequels and prequels of this anime. I noticed that previous posts, that Pokemon anime must spawned to multi sequels and prequels, side stories and specials.