Why a new design? If a teardrop is not comfortable enough, you might want something larger. If you live east of the Missippi, rain happens, usually on the weekend while you are camping. If you are camping rustic, you might want to bring your own shower. And if mother nature calls in the middle of the night, you don't want to trek down to the outhouse or bathhouse. Some people are talking about camping longer than a weekend. Some of them want more than a TD. Some people want a tiny trailer to flee hurricanes etc. So with all that in mind, let's see what we as a group can come up with...
Here's a couple requirements I think we should include.
Ability to stand up inside it.
Ability to cook inside
Ability to go potty inside
Ability to take a shower inside
Ability to use a bolt together trailer
Ability to sit and eat inside
Simple construction
Lightweight
Can be towed with a medium sized car
Adequate storage
Yes, we are packing 10 pounds of RV type stuff into a 5 pound trailer, and there will have to be some tradeoffs as we proceed into the design. But hey, isn't that what makes it fun?

So what did I miss?
Mike...