[xcode4] How can I build for release/distribution on the Xcode 4?

The "play" button is specifically for build and run (or test or profile, etc). The Archive action is intended to build for release and to generate an archive that is suitable for submission to the app store. If you want to skip that, you can choose Product > Build For > Archive to force the release build without actually archiving. To find the built product, expand the Products group in the Project navigator, right-click the product and choose to show in Finder.

That said, you can click and hold the play button for a menu of other build actions (including Build and Archive).