From Decred Forums:

It was mentioned on slack/IRC that this DD was technical and didn't make the release tangible for the layperson. Here's a breakdown of the most important parts of this release.

Stake version soft fork

In order to enable hard fork voting, we implement a soft fork that makes use of the existing block version in block headers, vote version and the stake version in block headers. Those familiar with Bitcoin may be aware that soft forks are implemented via the block version in the block header, where the network begins enforcing and rejecting blocks of lower version at certain activation thresholds, e.g. if 75% of the blocks in a trailing window of 1000 blocks are version 3, blocks with version less than 3 are rejected by the network. This process is entirely controlled by the PoW miners, so in Bitcoin, this process depends only on the PoW miners and not the rest of the network. In Decred, we require a second version in the block header to enable hard fork voting, called the stake version, and this version being incremented corresponds to the start of voting on a new set of issues that are encoded in votebits that are part of each vote cast by stakeholders. Decred uses the existing Bitcoin method for incrementing the block version in its block headers, but to increment the stake version, the block version must already be incremented and 75% or more of the votes cast in a stake version interval must be of a particular version, e.g. version 3. The rules for starting a new voting period can be reduced to asking a couple straightforward questions:
Did all the PoW miners upgrade to the latest dcrd release?
Did 75% or more of the stakeholders voting in the last stake version interval upgrade to the latest dcrwallet release?
If these 2 conditions are satisfied, the stake version is incremented and the next voting period begins. There is a third condition, but it is more technical and messy to explain, so I'll gloss over it.


If you have any further questions about the release, feel free to ask.