Go into the Market from a computer and find your app. Go to the contact developer section of the page, and send the developer an email to find out more information. Or, some apps have ways within the apps to contact the developer. If you can at least get into the app on your phone, you can try that way, as well.
It'll take time. The Galaxy Nexus is the only official ICS device on the market and it's only been out for a couple weeks. I'm actually surprised how quickly I'm seeing updates for apps given the fact that it's the holiday season. Many companies are in hibernation mode the last couple weeks of the year.