It looks like we have about nine months to go before Android Silver absorbs the Nexus program. Google is expected to launch Android Silver in February of next year. This news comes just one day after we learned that the Nexus 6 does not exist and the Nexus program is done for.
The Nexus program was originally targeted at developers, but seems to move on to a more mainstream audience over time. Android Silver would be an initiative that has Google partnering with manufacturers to release devices that run stock Android. Google would even handle some advertising, something that a Google Play Edition device has never seen. Nexus devices get advertised, but nowhere near the amount that Samsung or even HTC puts into its smartphones.