This has been making the rounds on the 'bent sites, but I hadn't seen it here yet. So, I thought I'd post it up.
http://evolvetrikes.com
This is the closest thing to a Brompton trike I've seen--everything stays connected, chain on the inside, fast fold, etc.
I hope these guys find someone to roll out their product soon; I know I'm definitely interested in one.
ECB
Disclaimer: I am not connected to Evolve Trikes in any way.