Notice how the lyric right after says "765" and some other Japanese? They're probably showing the lyrics of another part of the song or something.
The line says ARE YOU READY! I'M LADY! 765プロ・レディーゴー (which would be "765Pro, ready, go"...or "lady, go", if that's how they're wingin' it), which isn't in the song unless they extended it from the TV size for the game. I think it's just normal song info XD
I'm also thinking READY!! may end up being PS3 exclusive. Bandai Namco is sort of known for releasing exclusives on PS3 re-releases. I *hope* it isn't true. After all, the 360 version only has had 1 DLC song so far that works with quintets (Honey Heartbeat). There's so few quintet songs that I really would like to see READY!! on 360. I feel like PS3 users wouldn't have anything to complain about if 360 did get it. After all, 360 users would have to pay 1200 MSP for it. I think it's fair. But, as a 360 player who doesn't intend to convert to the PS3 version, I'm biased. 
My bet is they did this on purpose. Just looking at the number of videos for it on YouTube and NicoNico and the number of times I see it listed on the 360 PV leaderboards, it feels like that song probably sold *really* well on the 360. If they can make the PS3 users pay for it as DLC too, why not?
Honestly, I doubt NBGI would keep it exclusive forever...that being said, I really like the song READY!!, but I think I'd rather 1200MSP (or 600MSP, if I'm lucky) Honey Heartbeat. READY!!'s dance in the previews looks awfully static for such an energetic song.
However, there certainly needs to be more quintet-friendly songs in iM@S2. It's rather disappointing that there's only 4 of them available by default XD
Also, I agree with you on the DLC thing. I think Kyun! Vampire Girl has been the most popular song that's been released so far. The accessories, too -- I think I see the most videos and pictures with the fangs or the nails (or both). Maybe they didn't save the catalog because releasing it in October would be "predictable" or something.
Or they had another catalog leak and were too lazy/proud to pull it back this time XD