I am torn when it comes to this matter, on one hand this is an English Patch so they really should be in English but to get them even close to looking right seems like so much effort when the game already has Song Previews that help you easily identify what you are after and I've even seen people not want the English Titles on the previous Taiko, almost doesn't seem worthwhile.
Can't forget about the DLC, even though we can patch them to be English its a hassle.
On another note before we get that nice shiny new 1.0 update that lets us use the games update as well I toyed with getting iOS Taiko songs into the 3DS version and had some success
This is another reason I'm leaning towards just keeping Japanese Song Titles, they are much easier for me to re-create when it comes to Custom DLC as opposed to me spending way too long trying to get English to fit, porting songs is already a chore on its own, already have to let them auto play a few times till I get them to end correctly and take me to the score screen.
Now... if only I could find more up to date pack of iOS Songs... what I have is like a year old.