I got my uncle hooked on the first season. He's been bugging my mom and I for months about when Season 2 will be on DVD (he doesn't get BBCA).
Chase does have an Australian accent, but it's fairly subtle compared to many I've heard. The character was written as being foreign born/raised. I think the writers of House believe the audience assumes House is only treating local patients (which actually seems odd if he's as famous in the medical profession as they claim he is), hence the patients end up being American.