We've redesigned all the tree components (e.g. File Explorer, Outline view) to make the visual hierarchy more clear. This will likely impact any custom themes that you're using.
PDF: Improved text selection.
PDF: Added menu for embedded PDFs.
New behavior for "Open to the right" as well as the Ctrl/Cmd + Alt + Click modifier. Instead of always creating a new tab group, if there is a tab group to the right of the current tab, it will open the link in that tab group.
Outline: The outline view now supports keyboard navigation and preserves folded headings.
Obsidian Sync: Improved how Sync handles changing the casing for folder names (e.g. "some folder" → "Some Folder").
No longer broken
Collapsing items in the file explorer will now look visually better (previously the fold indicator of child elements would also appear to collapse as well).
Bookmarks: Fixed bookmark group not being populated in the Edit Bookmark modal.
Bookmarks: Hover preview no longer immediately hides after opening.
Bookmarks: Opening a bookmark with "Always focus new tabs" disabled will now still focus the newly created bookmark.
Spellcheck is now enabled when renaming files from the file explorer or from the tab title bar.
Backlinks: Fixed mod-clicking on backlinks not respecting the "Always focus new tabs" preference.
Developers
App will no longer show errors when plugins don't provide a "Component," to renderMarkdown, they will now just show a warning.