So far since the launching of Nexus series Google is been released a successor model yearly, First Nexus series device was launched back in 2010. For this year September is approaching and so far we don't have any concrete news from Google, but that doesn't means there will be no nexus for this year.
However, most of gadget experts believe that Google will be releasing its flagship device by the end of Q4 of this year. As i mentioned above, Google is not revealing anything regarding its upcoming Nexus 6, Initially Google senior VP Sundar Pichai, confirmed existence of Nexus 6 and suggests device won't be released in first half of this year.
On the other hand Google typical release dates are also pointing towards launch and release in fourth quarter, Google already made it clear that they will be releasing Android L this fall, so that's why launch in October with a release in November seems pretty much possible.
Device is expected will be having 5.2 inches display with a screen resolution of 1440 x 2560 pixels and Pixels Per inch will be 564. Rear camera of device is expected will be of 13 MP while front facing sensor will be of 2.1 MP. As OS device will be having latest Android L on board. I am sure, if these Specs are accurate surely device will be fantastic enough to compete with its competitors.