Aye I've got stuff grouped but like with the lack of folders feature, there's no way I can see to label groups. That too would have been fine, to be able to put a label to groups such as "Imaging Apps" and then when you use the inline type to search function, you could search for a labelled group as opposed to scrolling all the way to the right for labels starting with later letters of the alphabet.
Zoom out to view all apps and then right click on a group. it'll bring up the context menu at the bottom including the option to "name group". I have "core apps", "news etc", "video and music", "people" (from contacts you can pin fav people to the metro screen as well for quick access )' "tools", "games" etc...
Keep in mind you can uninstall or just unpinned all the preinstalled freebie apps if you don't want clutter or just your own apps.