I've just finished reading hr 669 and have to say that while it does need to be cleaned up, it seems like a good idea. Its goal is to limit the potential for damage done to the environment, economy and native species.
HR 669 allows for special permits to be granted for education, research, and display (zoos, etc). You want to have a python or hamster as a pet? Too bad. Yes, that sucks. But so does trashing the ecosystem. Look at Australia and the feral cat problem there.
I browsed a number of the sites of people who oppose this bill. Many of them are involved in issues such as recycling, reducing our cabron footprint, etc.
Plastic bottles don't breed (even if they seem like they do). Animals do. If this came to Canada, I would support it provided some of the wording were cleaned up. If cats were declared non-native (which they technically are), I'd have to find a new home for mine if I left my province, or would have to get a special permit to move with them. When they pass on, I would find some in the SPCA or somewhere else and adopt. When there are none left in the country, I will be sad, but there will at least be a reason for it.
The proposal doesn't suck. The need for it does.