The big news is the Intro Puzzles has been updated almost beyond recognition.
For one thing, it's now called "Intro Puzzles", where the old version was still "Tutorial Puzzles". Not sure when the name changed, but it's been a while. The old page should redirect to the new page.
The main Intro Puzzles page has been split into sub-pages. So you'll now see pages like Intro Puzzles/Electron Density. The new format should make for easier navigation with less scrolling. On the main Intro Puzzles page, there's an icon for each puzzle. Just click on the icon to get the help for that puzzle.
Each puzzle page now links to the next and previous puzzles, using the same icons.
The new format is also a lot easier to deal with in the wiki editor. I'd still recommend using a separate external editor for major changes, but smaller pages make the wiki editor more palatable.
The text for each puzzle page has been updated, and new images added. In many cases, there's a detailed "cheat" on how to solve the puzzle. My take is that is someone reads that far, they're really stuck, and getting them un-stuck may keep them going.
Most of the puzzle page now also have some technical information about what's going in the puzzle, a little more background on why the puzzle matters.
The "Rebuild" puzzle is now gone, and Remix has taken its place. Remix still needs a new video, but Madde's Rebuild video is still there for the moment.
The Flippin' Sheets puzzle is still a bit of problem, but the help has a new procedure which seems to work more consistently.
Along with these changes, there are several new pages, mainly in the Glossary category. I'm trying to add links to these new and updated definitions as I go. So you now have N terminal and C terminal, and more.
For the next phase, the (very loose) plan is to continue refining and refactoring the existing pages, mainly with an eye toward new players.
I've also started to update the main page, reformatting things slightly and removing some "new" links that stopped being new a while ago. I'm trying to update the main page at least once or twice a week, just in case anyone ever goes there.