Nexus 5: What we expect about the announcement, specs, and release date of Google's next smartphone

What we expect

October reveal date
We're still waiting for Google to send out invitations, but multiple sources point to an October unveiling for the Nexus 5. According to a TechRadar report, Google will announce and ship the phone in the last week of the month. Other sources, while not quite as specific, have also mentioned an October introduction.
This fits into Google's pattern as well. Last year's Nexus upgrade was also scheduled for the early autumn time frame, before Hurricane Sandy's interference pushed back the date.
Android 4.4 KitKat
The Nexus 5 should be the first smartphone to run Android 4.4 KitKat, Google's next OS iteration, out of the box. Google has already formalized the platform, but the details are a complete mystery. The fall time frame falls in line with previous platform releases; Android 4.0 came in October 2011, and Android 4.2 showed up in November 2012.
LG will make it
All signs point to Google again calling upon LG as the hardware maker of choice for the Nexus smartphone line. Documents found in the FCC tell of a model called LG D820 with specifications not entirely unlike the G2's, which is the source we expect the Nexus 5 to stem from.
Biggest Nexus yet
The Nexus 5 should have a 4.96-inch screen, which would make it the largest Nexus smartphone to date. We should look for the same 1,920x1,080-pixel HD display as the G2's, which equals a 444 pixel density.

The Nexus 5 form factor does not stray far from the LG Nexus 4's.

(Credit: FCC)

Body shape
Thus far, leaked images suggest that the Nexus 5 will maintain a form factor that doesn't stray far from the LG Nexus 4's. Early photos of the device, however, do not show the same design flourish or patterns on the rear.
Hardware
The Nexus 5 should be able to hold its own against the competition thanks to the quad-core 2.3GHz Snapdragon 800 CPU. Bolstered by 2GB RAM, LTE support, and NFC capability, the handset is expected to employ wireless charging capability and a 2,300mAh battery. Leaked benchmarks results have the Nexus 5 outperforming all other Android devices and rivaling Apple's iPhone 5S.
Carrier support
FCC documents indicate that the Nexus 5 is equipped for penta-band HSPA+ and multiple LTE bands and should support all four major carriers in the US: Verizon, AT&T, T-Mobile, and Sprint. This could mark the first time that Google is able to offer one device across all top-tier carriers.

http://reviews.cnet.com/google-nexus-5/