Actually according to the newspaper today, it appears that couples where one of the people is not a US citizen so the spouse does not have a social security number, those couples will get nothing, not even the US citizen!
You don't have to be a US citizen to have a social security number. My BIL is a permanent resident (with an SSN), and he and my sister are getting a stimulus check.
I'm going to second what everyone else says. Our income last year was about $26000 or so. We got a $900 check ($300 for me, $300 for DH, and $300 for DD). My sister and her husband made $36000 and are getting around $1200 (for sister, BIL, and nephew). I think the way this was advertised was very misleading.
The PP is right - it depends on how much tax you pay in for the year as well as your AGI.
Actually according to the newspaper today, it appears that couples where one of the people is not a US citizen so the spouse does not have a social security number, those couples will get nothing, not even the US citizen!