In the past the way that this works is that Android's new features are announced at Google I/O and then followed up with a device launch on which they make their debut.
That's really what the Nexus programme is about, and there was more than a hint at what you'll see on the next Nexus, delivered today by Dave Burke, VP of engineering on Android at Google.
Burke introduced a number of hardware-dependent features when talking about Android M. The biggest is the fingerprint scanner that sees native support in the future version of Android. Android M will support Android Pay, and fingerprint scanners will be a core part of authentication, so it's a dead cert that the next Nexus will have that hardware.
Burke also said "Coming to a device near you soon," when talking about native support for USB Type-C. Again, with the march of USB Type-C now underway (including the recent MacBook and Chromebook), it's a pretty strong hint that we'll be seeing it in the next Nexus device.
Our first introduction to USB Type-C on Android was in the Nokia N1 tablet we saw at MWC 2015. At the time we remarked that it would make a wonderful Nexus tablet, but there's already rumours circulating that Huawei might be lining up a Nexus device.
Oh, and we also spotted on the list of unannounced features the suggestion that Android M would support a stylus too...
There's no word on when we might see new hardware, but we'd expect a new device to make its debut with Android Milkshake (?), ready for the support of Android Pay later in the year.