Well for one thing the whole map got a visual update
They took away deathfire grasp and are going to replace it soon
and than there are jungle items
Jungle items now build off of machete and there are just a set of them each with enchantments
Also you can only smite big or epic monsters
Stalkers blade: Lets you smite champions, doing a small bit of true damage and steals some speed from them. You will see this the most
Trailblazers: Deals splash damage to jungle camp, and heals you. Usually seen on people with poor clear like rammus
Skirmishers: Lets you smite a champion. It doesent deal any damage but you deal extra true damage to them on hit and take reduced damage from them. See this on 1v1 champs
Poachers : Smiting and killing monsters on the enemy jungle gives you bonus rewards. You will rarely see this. Its a counterjungling item
Enchantment Juggernaut : Gives bonus health. Its gonna be replaced next patch and will give you 25% health and a sunfire effect
Enchantment Magus : Gives AP and cdr
Enchantment Warrior : Gives ad cdr and physical pen
Enchantment Devourer : Pretty much a reworked feral flare, it stacks champ kills and big monster kills and gives you magic damage on hit
also got a couple new normal items
Zz'rot portal : Places a portal that spawn void creatures. They go to the nearest lane and attack enemy turrets. They die after they get aways away from the portal. It gives you mr and armor. Every fourth void creature gains damage based on your armor and mr
Essence Reaver : Gives 80 dmg and you gain mana every time you aa
And we got a set of new elixers
Elixer of iron : You have 25% more size slow resistance and tenacity. You also leave a path that speeds up allies
Elixer of ruin : extra health and damage to towers. Also powers up nearby enemies
Elixer of sorcery : Extra ap and true damage to champs and towers
Elixer of wrath : 25 ad and lifesteal. Kills and assists extend it by 30 seconds
We also got some changes to the jungle creatures
Baron now has a better kit of abilities and his buff only gives ap and ad but massivly boosts minions your near to
Dragon no longer gives global gold but has a stacking buff each time you kill it
First time : % increased ad and ap
Second time : % Extra damage to towers and buildings
Third time : % extra movement
Fourth time : Extra damage to minions and monsters
Fifth time : Doubles all other bonuses and your attacks burn for true damage. It only lasts 180 seconds and is lost upon death.
Jungle objectives now give you rewards when you smite them
Red buff : Healed for a lot of health
Blue buff : Gain a lot of mana
Gromp (used to be wraith) : people who attack you are poisoned
Wolf : Spawns a little spirit that wards one area for a little bit
Razorbeak : Used to be the camp of wraiths : If you are detected by a ward in the next 60 seconds it is disabled and you gain vision of it
Krugs (used to be golems) : Every sixth basic attack stuns
Also turrets got changed
The inner turret has a shield that shields from champion attacks and gives a shield to nearby allied champions while its shield is up
The inhibitor turrets and the nexus turrets have a laser that ramps up over time
And now the champions
First off new champions
Kalista : http://na.leagueoflegends.com/en/champion-reveal/kalista-spear-vengeance-revealed
Rek'sai : http://na.leagueoflegends.com/en/champion-reveal/reksai-the-void-burrower
Bard (not out yet) : http://na.leagueoflegends.com/en/champion-reveal/bard-wandering-caretaker
Got an update! http://euw.leagueoflegends.com/en/news/champions-skins/champion-update/champion-update-tristana
Viable champs
http://www.lolking.net/charts
zed is dominating midlane and lee sin is STILL destroying jung.
Ahri got nerfed
Akali got nerfed
Got changed. His q is now a skill shot and his w has a delay
his q is now an aoe skill shot. If it doesent hit it stays above ground and will attach to first pearson who comes near
Im sure there is more, but that is the rundown.
If you want to get SUPER in-depth
Patch 4.17 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-417-notes
Patch 4.18 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-418-notes#patch-updates
Patch 4.19 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-419-notes
Patch 4.20 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-420-notes
Patch 4.21 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-421-notes
Patch 5.1 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-51-notes
Patch 5.2 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-52-notes
Patch 5.3 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-53-notes
Patch 5.4 : http://na.leagueoflegends.com/en/news/game-updates/patch/patch-54-notes
Also, dont know if you care but the ultimate skin for 2014 came out in febuary (yes, it was late) : http://promo.na.leagueoflegends.com/en/dj-sona/