Nexus 6 has just gotten FCC approval, with plenty of time to spare before preorders start this Wednesday, October 29th.
There are two different models that have passed the FCC labeled with ID IHDT56QD2 and IHDT56QD1, but we can assume that they are the XT1100, which is the international variant, and the XT1103, which is the North American model, respectively.
The filings aren't labeled as Nexus devices, but come from Motorola and have the same dimensions (159.4mm x 83mm) as the Nexus 6, so it's pretty easy to make the leap. The device also shows the other wireless tech that you would expect, like Wi-Fi 802.11a/b/g/n/ac, Bluetooth 3.0 and 4.0, NFC, and Qi wireless charging.
The North American model has a solid number of wireless bands inside, including CDMA for Verizon and Sprint, GSM for AT&T and T-Mobile, and LTE bands 2, 4, 5, 7, 12, 13, 17, 25, 26, and 41. Oddly, while the international version has the usual GSM bands, the only LTE bands it supports are 5 and 41, which only help in China, South Korea, and a couple other regions.