This is very cool, now you can get some pre-release information on exactly what formations are available for each army. Yes, you can see many of them. How? Check this out.
On the Games Workshop site, GW has graciously, (I mean it, thank you), provided us with one click (non money savers) bundles, that includes the entire formaton. So to see some of the new apocalypse formations for your army..... simply go to the Games Workshop site and look under your army. There is now a section called Apocalypse formations.
I have spent a good half hour reading through these for some insight, so its great fun. Just to make it easier for you to do the same, here is the 40k GW link
Here are some examples.