I believe that we should base the "perfect Altera" off Earth. Just like the above suggestion (sorry but I never got around to learning how to quote
) the Equator should generally be desert, with mountain ranges and swamps scattered throughout. The Northern part (which will be where we will live) will be generally a giant forest with oceans around it and some plains spread throughout. This would be geographically correct and the more to the North we'd go, the colder the scenery will feel (close to equator will be pretty bright, whereas closer to the pole, it should be getting touch darker.) Of course, random swamps here and there with beautiful rivers cutting through forests will also add the effect.
All this isn't, unfortunately, something one person or a group of about 5 people can do within a week, and so it will probably take a little longer then the above mentioned week. However, I do believe this is highly possible with the new tool that Lars is using and therefore I believe future Altera will be by far greater then anything that pesky Mojang could ever imagine.
Great work on these biomes by the way all of you. Bravo, and I hop to see some more in future