Apparently, according to 2ch’ers that have managed to get the issue of Dengeki Games, Ys vs Sora no Kiseki will be released on 7/29 for 6090 yen.
No mention of a regular or special edition.
Apparently, the Dengeki article is 8 pages, according to people on 2ch, and that Xanadu is the set stage for it.
I’ll see what else I can dig around on there. I’ll report more when I can find it.