I created a creative superflat world with default settings and at the spawn it was generated a terrain very similar to the old beta generator.
I tried to regenerate the world with the same seed and now it works well.
Environment
Windows 8 Pro (64 bit)
Java 7 update 9 (64 bit)
Copy of:
https://mojang.atlassian.net/browse/MC-204
https://mojang.atlassian.net/browse/MC-315
I'm sorry for the inconvenience.