I think what fhw was implying that the main speakers in HT use are for dialogue, surround sounds or general noises you hear within a movie. But for music, there is constant feed of sound in a variety of ranges in which speaker selection becomes a little more important for its individual tonal qualities. I certainly could listen to a couple of speaker brands with a dvd playing but chances are i would not really pick out the sound of the speakers very well. But if i were listening to music the speaker qualities should be more evident.
All that aside, the M60s are excellent for both applications. Take a quick search in the forums for M60s and reviews. Several have been posted recently which should give you a good idea of the tonal qualities of that speaker.
As for the sub issue, it really adds some oomph in the lower end bass for HT but if you are planning on picking one up in a couple of months then i wouldn't concern yourself too much about living without it for now. The m60s don't exactly rumble (their bass is very tight) but they will hit some good low chords.
enjoy.
