Upgrade my 970 or wait?

First, wait for what? Like the other guy said, at 1080p they are roughly the same (in DX11 games) overall (and the 970 even beats the 480 in certain titles http://media.bestofmicro.com/ext/aHR0cDovL21lZGlhLmJlc3RvZm1pY3JvLmNvbS9UL1kvNTkyMDU0L29yaWdpbmFsL2JmNC1mcHMtMTl4MTAucG5n/r_600x450.png ). However the 480 pulls ahead by 10% or more in DX12 games and the one with 8GB VRAM helps as well in newer titles that are becoming VRAM hogs even at 1080p (like the new Dues Ex).

Still, that's more of a lateral move in the larger picture of things. No need to upgrade until you start playing games and come across stuttering issues with the 970's 3.5GB direct access VRAM issue. And upgrading to a 1070 is overkill for a 60Hz 1080p monitor even at ultra and high AA.