Note this is pretty old, October 9, 2024
Tl;dr - from the website (https://deno.com/blog/v2.0):
Today, we’re thrilled to announce Deno 2, which includes:
Backwards compatibility with Node.js and npm, allowing you to run existing Node applications seamlessly
Native support for package.json and node_modules
Package management with new deno install, deno add, and deno remove commands
A stabilized standard library
Support for private npm registries
Workspaces and monorepo support
Long Term Support (LTS) releases
JSR: a modern registry for sharing JavaScript libraries across runtimes