My guess is a pack of 5 songs + Never Gonna Give You Up (which I'd buy, I never really paid attention to the meme, so I didn't get burnt out on the song
J Geils Band - Love Stinks
Roxette - Listen to Your Heart
Heart - Alone
Stevie Nicks and Don Henley - Leather and Lace
Something along those lines. As badly as I want The Eagles in Rock Band, I doubt it. Same with Zeppelin or GnR. Part of me can't see them hyping the most requested song ever and it's just Rick Astley though. Last year's Valentine's pack was my personal favorite, so I'm sure whatever it is I'll be buying it and I'm pumped for the announcement.