Yeah... IF Ayu is going to tour or even just create some kind of presence outside of Asia, it's gotta be now, or in the next couple of years, otherwise the timing won't work out.
Also, this is Ayu we're talking about. In her TA post, she said to believe in her whatever she does. So I'll do that. I think that Ayu understands the kind of image she has, and what she can and cannot do if she is to expand her market beyond Asia. Now, one of the first things she probably already understands is that she can't do the same thing that BoA and Utada has done-- namely changing their image to try and suit mainstream American taste. This would pretty much destroy Ayu's image in Japan which made her successful for so many years in the first place. Ayu's known to be honest and reflecting. Look at what happened when the Sparkle lyrics were first released and how that was received in Japan (and even on this forum)? Do you really think that a hormonally charged US album in English would work well for Ayu? Her loyal fans who fell in love with Ayu for her signature music style probably won't fall in love with a BoA/Utada-esque debut in America. I think Ayu understands this herself. There's no doubt that Avex and Max Matsuura will consider all this information because they just have to think about all this before they do anything.
So yeah, I don't think there's any need to be afraid that Ayu will try to be someone else in order to gain popularity in the US. Also, the comparison to J-rock visual-kei bands is rather weak because as people have already pointed out, VK bands don't have much money in all this even in Japan anyway. That's why they branch out. Ayu is pretty much the complete opposite. She has all the money in Japan. If she is to branch out, it's to meet her fans outside of Asia, purely because she has the desire to do so and not because she wants the money.
For these reasons I think it's likely that she will be herself.
Also, good viral marketing on the internet by Avex would be great. I know Avex has a crazy marketing force. If they manage to do what they did during A BEST, but in an evolved way to suit this even more digital era, then hey, you'll never know what can happen then.
As far as this goes though, it'd be nice if Ayu can as a result hold a few extravagant lives outside of Asia. I'd love to see that happen.