I have a gaming PC besides WiiU as far as current gen goes (although i have a PS3 for last gen).
Right now i don't care for neither the PS4 nor the XBO exclusives, but if i had to choose i'd go for XBO since i'm a little curious about Killer Instinct.
As for what to choose between when the time comes for purchasing PS4 or XBO? Whichever version of FFXV and Soul Calibur 6 is the best. So PS4 is the most likely future purchase.