Added:

• 2 new default classes: Farmer and Artisan
• Vein mining, unlocked at Mining 10
• Tree chopping, unlocked at Woodcutting 10
• 2 new skills: Farming and Smithing
• Right-click harvesting, unlocked at Farming 10
• Confirmation screen to class selection

Changed:

• Class selection screen now shows up upon joining a world/server for the first time
• Mob scaling is no longer based on Combat level. Instead uses class level which is hidden but based off total xp gained

There's probably more because this is a MASSIVE update but I can't think of anything else right now.