The release notes are here.
The main highlights are that the Transplant plugin functionality has now been brought into core. It is now called ‘graft’, although the Transplant plugin will still work.
The other highlight is the introduction of an official large files plugin. It’s based on all the previous work done. They’ve decided on the name largefiles. If you’ve looked at the others, then the approach of this one will be familiar.
Basically, a large file (by default defined as anything larger than 10MB) will have a placeholder in the actual hg repo. This will be a key into a secondary store that contains the actual large files.
When you update to a revision that contains a large file, first the local repo cache will be checked to see if this version is stored there. If it is, then there is obviously no need to download anything.
If it isn’t, then you MUST have access to the central store, as HG will copy the large file to the cache, and put it in your working directory.
There is also a corresponding update to TortoiseHG.