You'll be able to transfer the license within the Goolge Marketplace. The only thing that would hold you back is the filters in Google Marketplace which identify your location and supported OS.
The problem with not being able to see the Slingbox Mobile for Andriod are filters within Google's Marketplace. If you're using an unsanction operating system, or are from one of the countries that do not currently support paid application then you won't be able to see it within the marketplace. This is because the Slingbox Mobile is a paid, copy-protected application.
Available per country (http://www.google.com/support/androidmarket/bin/answer.py?hl=en&answer=143779)
Unavailable per country (http://www.google.com/support/androidmarket/bin/answer.py?hl=en&answer=138294)
Work around for non-rooted phone (http://www.google.com/support/forum/p/android/thread?tid=441baa3452369f21&hl=en)
Work around for rooted phoes (http://www.google.com/support/forum/p/android/thread?tid=2a55855a017b346c&hl=en)
Work around for Froyo Users (http://www.androidcentral.com/how-get-your-paid-apps-back-froyo)