I worry that I may be pulling things off topic, but I am going to play devil's advocate a little bit. The general rule is not that Push means to Push away, as you say ringkichard. It is actually much more specific than that. It is push 1 zone in the opposite direction from the caster. Thus, when Force Wave says to Push them 1 zone away in the same direction, it does not necessarily mean the same thing as the general rule. "Away" can have a much broader meaning than the general rule for Push.
First off, it seems to me that Force Wave was worded that way to ensure that you could not move different creatures in different directions. This, however, would imply that such a thing was possible to begin with. If you don't ever have a choice in the direction pushed, how could you ever possibly move two creatures in different directions? Since the spell is a range 1-1 you'll never have the issues of the caster standing at the diagonal OR the issue of them being in the same zone. Thus, neither of those situations will ever occur to give you a choice in direction. The only other possible thing to give you a choice is if the effect itself allows you a choice.
Now, the word "away" can legitimately be defined as increasing the distance between two objects, rather than moving in the opposite direction. Thus, it does seem like a reasonable ruling to say when you use Force Wave you can choose any direction to push them in except into the caster's zone, but then all of the creatures have to be moved in that direction.
Personally, I would tend to still use the spell as pushing in the opposite direction just to avoid any hassle or argument, however if someone else wanted to use it otherwise I can see their point and would not be able to argue against it. I could actually even see someone arguing that the text on Force Wave means pushing the creatures "away" from the target zone instead of "away" from the caster, which would actually allow them to be pushed in any direction including towards the caster. I don't personally believe this was the intent, and would probably argue against such a case, but it isn't completely without merit either.
I apologize if I am making this more complicated than it needs to be, ringkichard. I just thought that since this was a thread about ambiguities with Push effects, I would throw in one I think really is not covered very well.
