No, the mega for series crossover from DC and CW expected later this year will not be a transcendent orgy of pop music and dancing. Because that would mean Berlanti and his array of showrunners and producers looked out at the onscreen talent afforded them and said: yes. Motherfucking musical.
Source: io9 – This Year’s DC/CW-Verse Crossover Should Totally Be a Musical, You Guys