Yup, it's a single. From what I've gathered, it's called "Wildflower & Cover Songs:Complete Best 'TRACK 3'". On Disc 1 all the new songs (Tamashii Revolution, Roll Over the Rainbow, Free Planet and Wildflower) from this year. Disk 2 is a compilation of all the covers from her previous singles, as well as 3 new ones. I think there's also a Disk 3 which has an acoustic version of one of the new covers.
I guess you could call it a mini album of sorts.
More info and full track list here
Also, it seems that Superfly updated her website to a more stylish and profesional theme. Nice.
