Every Minecraft update that changes world generation. They will be reset with 1.7, as canyons are now confirmed.
The canyon biome does look cool! But it's something we all don't truly know what it is just yet. We can wait for the next update for it probably.
I believe that the wastelands are reset every update, because it was about 2 months until the wastelands were reset on smp1. I don't know when they are reset, all I know is that I go there and get stuff.
that's why I said regularly I was on one thread and someone asked the dame question and he said my mistake that the yellow barrier near spawn inside the wastelands regularly gets reset every month.
I think you mean the yellow barrier near the spawn inside the wild frontier. The wastelands I think does get reset each update.
Yes, it's the frontier, because there is a yellow box with the spawn inside that gets reset each month, I think. With the wastelands, there is not a yellow box, which means the entire wastelands gets reset each update. The wastelands was reset when 1.6 came out. The next update, I think the wastelands will get reset again.