Qualcomm has announced the new Snapdragon 821 quad-core processor; the next in line from its current high-end chip, the Snapdragon 820. Although it doesn't give precise details on all the improvements made with the Snapdragon 821 over the 820, the company does state that it offers 10% performance increase.
Like the Snapdragon 820, the 821 uses a Kryo quad-core CPU, but can be clocked up to 2.4GHz speeds. That's a 0.28GHz increase over the Snapdragon 820.
Qualcomm states that the Snapdragon 821 will "set a new bar for smartphones, tablets, mobile VR head mounted displays and other new devices". We're also told to expect the first wave of devices powered by the processor to arrive in the second half of 2016. Which basically means anytime from now.
Qualcomm doesn't see this as a replacement for the 820, rather, it's been designed to "complement and extend the competitive strengths of the Snapdragon 800 lineup."
While it falls short of saying exactly which devices will be shipping with the new chip, it's very likely that we'll see it in the next Galaxy Note, which is due to be announced next month. It's also likely to be chosen as the processor for the next Nexus smartphones.
Given that Google has set out a list of specifications required for phones to be Daydream VR compatible, it's likely that Qualcomm released the updated chip to comply.
If Qualcomm wants to be the processor of choice for the next wave of high-end phones, it needed to make sure it has something on the market that's capable of powering Google's standard for mobile VR. It could also perhaps be because complaints of slow performance on the Galaxy S7 range in the US meant a more powerful processor was required by Samsung for the Galaxy Note 7.