And so begins the long list of Android devices that won't officially be updated to Android 4.0 Ice Cream Sandwich. Samsung's "Samsung Tomorrow" blog, in Korean, has explained why two of 2010's top devices, the Galaxy S and Galaxy Tab, won't be getting official updates to ICS. The short version: older hardware and a slew of customizations, including Samsung's own TouchWiz.
This shouldn't come as a surprise, folks, seeing as how Samsung just announced its initial round of ICS updates, and neither the Galaxy S nor the Galaxy Tab were on it. And neither device made our list of ICS update predictions, either. It sucks, but not every phone will receive and official update.
Your best bet will be the custom ROM route, and we guarantee you, you will see them.
Source: Samsung Tomorrow (translated)