Heck yeah!
I was actually brainstorming last night
You know how it seems people might be rear facing longer thanks to the SS1? I've noticed moms with kids who are at least a year old, maybe more, in their infant seats. If you have a seat that fits and works parents are less likely to run out and buy a new one, right?
So what if manufacturers designed an 'infant' seat that was rear facing ONlY but to 40 pounds?! It could be like the Tru-fit...a head rest to remove when they're very small, and a carrying handle. Then once the baby reached a certain weight, say 30 pounds, the handle is removed and the head rest is attached.
If you could buy ONE seat at birth that would get you to three and a half/four years old rear facing, wouldn't that be great?