Is there a way to check whether an app explicitly supports Resume or not? Is there any way to check whether an app explicitly supports Lion's new Resume feature or not? For example, as of right now, Safari supports Resume, meaning all the tabs are reopened, however in Google Chrome, this is not the case.
Most "Lion-Ready" apps will also support the new full-screen mode, so if you see the little full screen button, it is likely the application will also support Resume. However, there is no definitive list that I am aware of yet, nor is there a way (beyond a mention in the app's documentation) of knowing whether it will support Resume.

However, there is now a list of "Enhanced for Lion" apps on the appstore which might be a good place to start.