I tried upgrading my Galaxy S to ICS like I did my Galaxy S2.
I used the exact same steps. However, Odin froze and shut down. So, I unplugged the phone, powered off, and went to power back on in download mode. It didn't show any signs of life now. I've taken out the battery, put back in, but still nothing. When I plug it in, it doesn't even come up with the charging symbol.