Not a bad suggestion. Though, I will point out (if you want to get technical), even Cumulonimbus clouds look kinda flat from space (thunder clouds). Here is a satellite image of earth. See the storm cell past Florida, near New York? Those would be the thunder clouds you mentioned. There is also a couple near Washington state and Canada.
The other thinner, shredded clouds (more separated), are called Cirrus clouds (high clouds). Those look relatively flat too. There is some detail that you could put into thunder clouds for US2, but it may not look all that different.
What would be cool to see is the clouds moving in all directions instead of repeating the same animation like what you may have noticed in the live stream a couple weeks ago. Procedural clouds would be cool, not just for earth, but for any planet you spawn.
EDIT: Also, I forgot. I guess the jet stream helps keep storms coming in and out of their usual areas. Like winter storms coming down from Northern Alaska and into the midwest. So I guess the current way the clouds move on earth isn't all that far off.