Anticipating another skip year.
I don't buy OEM models any longer, so its Nexus for me. The main issues I have with the Nexus line are software related (camera options and speed, battery life, added features like multi window). Those can be improved on the N6 moving forward (or through community support).
On the hardware side, I'm too much a sucker for the contrast and black levels gained with an OLED panel (even if its mid range in quality) and I think 6" is too hard to give up (my Note 2 feels small now). The stereo speakers are just icing.
Unless those two things are also present on the rumored Nexus devices later this year, a better camera sensor, USB-C, and finger print reader won't be things I'm willing to trade up for.
The 805 chip set isn't showing any signs of aging either, but we'll what kind of power saving benefits come as a result of moving to a new soc. I'm sure Google will find a way to mitigate it regardless.