While you need to ask Microsoft you also need to be clear which Windows 8 you are going to. Windows 8 is accepted by most to be the one you run on laptops and Intel powered PCs.
Windows 8 RT is a restricted tablet where you can't install apps except from the Microsoft Store.
Which one are you looking at?
I may want to purchase a Microsoft tablet (which is the Windows 8 os) next year and my Norton 360 license is going to expire in 7 days. If yes, I would need to renew my license now. If no, that means I need to purchase Norton 360 Multi device to use it on the tablet. When this occurs, I will need to use Microsoft security essentials tempoary.