They typically release before the open with the conference call after the close (I never really liked the seperation of those two events). Omen-wise I don't think it makes a hoot to any companys' results and I think it's a mixed bag as to when companies report. I have noticed trends vs industry, etc. though.
What I've seen over the (too) many years is more bad earnings after the bell and good earnings before. Like here for instance. It doesn't mean anything all the time either way. It's just what I've noticed.
I agree with you though with the separation. Can't see where that makes sense.