So, there's a site in English dedicated to the IniD Arcade Stage game. (Thanks, Lai!) It's got locations for where the arcade game can be found, and a bunch of other useful and entertaining information.
There's also more detailed information on Arcade Stage 2. It does have two new courses, Akagi and Irohazaka. Yay!! If they had asked me to choose two courses I most wanted added, those would have been them. Must spend time over the weekend hunting down videos of the new course runs. (For research purposes, of course! Must... research... maps...!!)
Looks like Arcade Stage 2 is more expensive than the first one. Grr. I'm probably not going to actually play then, especially not with the PS2 version coming out. Based on the number of courses the PS2 version is supposed to include, I'm betting that Akagi and Iroha are included in that. This is a good thing.
On a completely unrelated note, for some odd reason my pocket tissues are distinctly cinnamon-scented. It's rather pleasant, though somewhat odd.