i think they will keep the free tracks.. but if u want to buy songs, like "black eyed peas - boom boom pow" then itll cost money.
WIKIPEDIA says that OCTOBER 1ST is the SET DATE for release.
wikipedia search : tap tap revenge 3
it will load up TAP TAP.
then u scroll down after clicking TAP TAP
and itll show TAP TAP REVENGE LADY GAGA.. THEN BELOW THAT IT WILL HAVE TTR3.
and it will say OCTOBER 1ST IS THE SET RELEASE DATE.
(which is this thursday in australia) unless apple APPROVES this APP earlier :)