Ok. Here's more:
Update 4: The Mushroom Update
Adding all mushroom-related stuff, including:
Truffle, Hammush, Mushroom Spear, Shroomite (and all things made with it), Autohammer, and all those other things.
(Sorry for rushing myself on this one)
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Update 5: The Plantera Update
Adding Plantera, The Cyborg, all Plantera Drops (besides Temple Key), Plantera's Bulbs (of course), the post-Plantera Dungeon (including all enemies/drops), Solar Eclipses (including all enemies/drops), the True Swords, and all other stuff. And all the post-1.2 crafting stations (besides Crimson-related ones)
Update 6: The Temple Update
Adding the Golem, the Temple along with the key, Biome Keys/molds along with their chests (besides the Crimson), all Golem drops, Pirate Invasions (all drops), and all Temple-related stuff.
Update 7: The Crimson Update
Adding the Crimson, and all relevant stuff, including the Crimson Chest/loot/key/mold.
Upd8 (Silly worldplay): The NPC Update
Adding all 1.2 NPC's, plus the following:
The Guide now has his crafting menu, the Merchant sells all his 1.2 merchandise, the Clothier now sells all his 1.2 merchandise, the Wizard now sells his 1.2 merchandise (Wait, did they even add any Wizard-bought stuff in 1.2?), the Arms Dealer now sells his 1.2 stuff... and so on. Floating Islands are also updated, with Sunplate Blocks and a Skyware Chest (along with its respective loot).
Update 9: You Feel an Update from Deep Below
Adding all 1.2 Underground/Underworld enemies, loot, and blocks, along with enemy banners, and Spider Webs (along with all of their loot). Plus, all the alternate ores are added (pre-hardmode AND hardmode).
Update 10: Like a Boss
Adding all boss trophies and masks. Also, the Mechanical Bosses can now appear on their own. Also, all the bosses will gain the chance to drop their post-1.2 loot (Book of Skulls, Slime Gun, etc.)
Update 11: The Moon Update
Adding the 3 different types of moon (ringed, orange, grey), along with the two Holiday Moons (with their corresponding enemies/bosses/loot).
Update 12: The Fashionable Update
Adding all 1.2-1.2.1 accessories/combinations not already added in the previous updates, also making accessories show on the character. Also adding all Dyes and the Dye Trader.
Update 13: The Update in Shining Armor
Adding all 1.2-1.2.1 armors not already added in previous updates, plus the Beetle Armor.
Update 14: See You Online
Adding online multiplayer, with a 50-player cap (can be lowered when hosting).
This will probably be the biggest out of all these updates.
Update 15: An Update Storm is Closing in Fast
Adding the Rain event, along with all corresponding enemies, and loot.
Update 16: So Much Wood
Adding all 1.2 wood, along with Spooky Wood and Living Trees (with their corresponding loot). Also, Wooden Chests will gain their 1.2 loot.
Update 17: The Desert Update
Adding all 1.2 desert stuff, including Pyramids.
Update 18+: To Be Announced
Remember, guys, this is just a suggestion.