I don't think this would work for me, either. I don't think any of the major cruise lines here would do it. Going from Florida, there are only a couple options; The Bahamas or the Caribbean. Going from the Mid-Atlantic, there are also only a couple choices: Bermuda, and New England / Canada.
On the Saga Rose cruise, did the passengers know how long they would be gone (example, 7 nights, 10 nights, etc.), or was that also a mystery? It didn't specify in the article.
2007 - Majesty of the Seas (Bahamas)
2009 - Enchantment of the Seas (Western Caribbean)
2010 - Freedom of the Seas (Western Caribbean)
2013 - Golden Princess (Alaska, roundtrip from Seattle)