Is there a way to regenerate my world without destroying affected blocks

I'm wondering if there is a way to regenerate my world but only affect blocks that are part of the seed. I.e. would update all the blocks in my snow biome to actually have snow on them, but not destroy my base that is in said location. Or spawn the multiple strongholds or spawn people in my already found town.

I don't have high hopes but thought i'd ask.

In past updates, biome changes have been retroactive. I logged into my original singleplayer world recently to find it was now a snow biome.

You can use a map editor (such as MCEdit) or a game mod (such as Bukkit WorldEdit plugin) to delete the chunks you haven't built anything in. When you explore them again, they'll regenerate using the most up-to-date method.

If you really want all the latest terrain everywhere, use MCEdit to copy your base and export it as a schematic. Write down the world seed. Start a new world in Minecraft using the same seed, then exit Minecraft and use MCEdit to import your old base into the new world.