mate that sounds like good news, we got our fiance visa 3 weeks ago and and that's the same message we got, and she had her visa delivered the next day, I know just how your feeling right now but keep calm and you will soon get your good news, from what I know if there was a problem they would have contacted her for interview, How many days since you submitted the application? we got ours in just 7 days.
Best of luck to you and anyone else waiting.
Carl.