In case you want to deploy a feature based RCP for more than one platform (with the delta pack): Do not forget to add the org.eclipse.rcp feature either as included feature to one of your features or add it directly to your product configuration. The org.eclipse.rcp feature includes all the platform dependent plug-ins and fragments (like SWT win32). So in case your export doesn't contain the platform dependent files (and fails to launch) verify that this feature is added…
Even if you do deploy to one platform only but do have a feature based RCP you have to add the org.eclipse.rcp feature. Otherwise you have to add all required platform dependent fragments yourself.