Kammala wannan magana: "E=MC2" ya fara a lamba daya a kan "Billboard" 200 tare da kwafi 463,000 da aka sayar, mafi yawan tallace-tallace na farkon mako na aikinta. A shekara ta 2008, Carey kuma ta taka rawar da ake kira Krystal a cikin "Tennessee" kuma tana da bayyanar cameo a cikin fim din Adam Sandler "Ba ku rikici da Zohan ba", tana wasa da kanta. Tun lokacin da aka saki kundin, Carey ya shirya ya fara tafiya mai zurfi don tallafawa "E = MC2". Koyaya ba zato ba tsammani an soke yawon shakatawa a farkon Disamba 2008. Carey daga baya ta bayyana cewa tana da juna biyu a wannan lokacin, kuma ta sami zubar da ciki, saboda haka ta soke yawon shakatawa. A ranar 20 ga Janairu, 2009, Carey ya yi "Hero" a
Bikin rantsar da unguwa bayan Barack Obama ya rantsar da shi a matsayin shugaban Amurka na farko na Afirka. A ranar 7 ga Yuli, 2009, Carey <unk> tare da Trey Lorenz <unk> sun yi waƙar ta Jackson 5 waƙar "Zan kasance a can" a wurin tunawa da Michael Jackson.