Voyager: Only Seasons 1,2 and 3 are available. DS9: Only 1 through 5 are available. TNG: Nothing at all, SD or HD TOS and Enterprise - All seasons are there. Movies: All are there.
Where are the following: Voyager: Seasons 4,5,6,7 DS9: Saesons 6 and 7 TNG: Everything - There is no TNG at all. There has ever been a single episode or season and now that the HD seasons have been released, they are not in the iTunes store (Australia) either.