From last two years Nexus flagship Smartphone is manufactured by LG Electronics, Since Nexus 4 LG is manufacturing partner of Google till Nexus 5. According to latest statement from LG it's confirmed that LG won't be manufacturing Nexus 6.
Recently LG's global communication director revealed that they don't know about details of next Nexus Smartphone. He further revealed that though LG know details regarding Android Silver program, but for this year Nexus Smartphone Google didn't ask LG to work on Nexus 6.
There are very rare chances for Sony and Samsung to manufacture next Nexus Smartphone, In that case only HTC and Motorola emerged as strong contender for manufacturing of next Nexus Smartphone. But so far both HTC and Motorola didn't made official announcement.
As for this year, HTC is allegedly manufacturer of Nexus 8/9. Device is heavily rumoured but so far nothing is concrete as Google didn't reveal anything officially. Nexus 8/9 also leaked recently and device is dubbed as "Volantis". On the other hand Motorola top executive didn't confirmed whether they will be manufacturing next Nexus device or not.
Initially rumours were swirling regarding discontinuation of Nexus Line-up but soon these rumours dies as Google top executive made it clear they won't be dropping Nexus line-up in favour of Android Silver. Back in June rumours of Nexus 6 sparks once again when Android official twitter account revealed about they will be introducing new ingredients feature in their Search system using a new hardware device which is most probably will be upcoming Nexus 6.