I am told that you can reserve an iPhone app name 90 days in advance, can I get around this by adding a placeholder app that says "Coming Soon"?
Apps that are not fully functional or that link to functionality that is not available but "coming later" will be rejected by Apple.
EDIT: Here are the guidelines.
http://developer.apple.com/appstore/guidelines.html
Not. Who would download an app that does such a thing?