Personally, I'm completely okay with it. The bottom line is, it will bring Free! more money and it expands the audience. I feel like it's a great thing. Even if you don't like dubs, nobody's going to force you to watch it. Just rest assured that the show we all love so much is going to be even more widely-loved than it already is!
I think they'll end up re-writing the Australia scene. Otherwise, they're going to have to do something hilarious and weird like Haru not being able to understand Aussie accents for some unknown reason.
All that aside, who would you cast in the English dub? Really, the only one I can think of off the top of my head is Kate Oxley for Gou. What are your thoughts?