I preserved root with Voodoo OTA Rootkeeper. As usual, the permissions on su were wrong after the update, but Titanium Backup picked up on that and offered to fix them for me. I accepted, it did its thing, told me to reboot, and all's well.
I looked at Google Now for ICS, but it appears that the developers haven't yet figured out how to enable voice input (which was one of the key features). For what I would want it for, I have a weather widget on the primary home screen and my home and work addresses entered in Waze, so I can live without it for now.