I have just uploaded release 4 of Nikola. Here are some of the changes in this version:
Previous/Next post links
Support posts with HTML "sources"
Site checking script (nikola_check)
Maximum image size in galleries
Image descriptions in galleries
Image exclusion in galleries
Special "draft" tag
Pretty code listings ("code galleries")
Easy theme tuning via Bootswatch
Support for WebAssets bundles
"Filters" for powerful file post-processing
Improved HTML output
Support multiple time formats in post metadata
Slugify tag names for URLs
Archive path and filename configurable
Galleries sorted by date (supports EXIF)
Rotate gallery thumbnails (EXIF)
Tag feeds in tag pages
Colorbox support in restructured text figures
Fix for content displaying too wide
As usual, you can discuss bugs or make feature requests at the nikola-discuss group and I love to know of sites using Nikola.
Hope you like it!