I kept hearing their single on XM radio and then I saw them on Fox's 'O.C.'...they're just one of a handful of retro-rock or 'revival' bands who're popular these days (see also Jet, the White Stripes, the Strokes etc.)
Interesting thing, their lead singer Robert Carmine was born Robert Schwartzman, as in Jason Schwartzman's younger brother (Jason Schwartzman of Rushmore and Slackers fame.) Jason had his own band (Phantom Planet something) and he actually did the theme song from the 'O.C.' I guess Rooney got their start opening for Phantom Planet around California. The Schwartzmans are nephews of Francis Ford Coppola, so their cousins are Sofia and Nicholas Cage. Pretty interesting family I guess.
edit: oh yeah, I was trying to figure out what "Sh-sh-shaking" was all about anyway. Is he describing a drug overdose, or a bad hangover, or is he just really sick?