Wow, what a great name! I much prefer it to Dorothy, I think Dorotea is just so spunky, yet old world classy. While I'm not a fan of Dorothea, I would definitely consider Dorotea for a future daughter.
Dorotea is the Italian (and Spanish) form of Latin Dorothea, known to mean "Gift of God." Also the Scandinavian form of Latin Dorothea, meaning, as well, "Gift of God".
http://www.nordicnames.de/Aussprache.html