I think I have figured out why Iowa has given us Isis logins. I think that it is mostly so that we can check the status of our financial aid stuff. I kind of doubt that the status will change from in progress to "you have an interview" I think it only changes to admitted or rejected. That's just what I think though and I often think incorrectly!
By the way, when you check your status, underneath the status it says "transcripts" and then it lists your undergrad school and says "not receieved". Don't worry about that. I called and the lady said that you only have to send in your transcript if you are accepted.