Good news! Phoenix Wright 5 has been renamed Phoenix Wright: Ace Attorney: Dual Destinies. The English version will be released this fall.
A few thoughts:
1. I suppose it's a good idea not to use the title Phoenix Wright 5. It's the fifth game in the series, but the fourth game starred someone else.
2. The game will be download-only. Some people are bothered by this, but I don't mind. Then again, I have no idea how downloading games works on the 3DS.
3. I'm not sure if the title refers to Phoenix and his law partner, Apollo Justice, or his new partner, Athena Cykes.