Good to know re: IU - I don't know that I'd get a TA-ship in the HCI dept. since this is a career change for me but maybe in a different department where I could use my undergrad knowledge. Kind of was hoping for that at Michigan but none of their available GAships have been in my field so that hope is dying.
But I totally understand how you're feeling. I mean, there's also the fact that other institutions have the April 15 decision date that they don't have. What are you supposed to do? Email daily and hope that they give you some aid within the next 3 weeks so that you can make a decision? The power balance here is tilted in their favor especially with providing the funding so late in the game.