Конечно я абсолютно ничего не знаю. А как насчет почитать что то кроме этого сайта? Например
http://www.minecraftwiki.net/wiki/Version_history Added Weather.
Added Statistics and Achievements.
New Items (Detector rail, Powered Rail, Birch and Pine/Spruce Saplings).
New Item Web. Cannot be found naturally.
SHIFT-clicking on something in a chest will immediately move the selected item(s) into your inventory and vice-versa.
Birch and Pine/Spruce trees now drop Birch and Pine/Spruce saplings, respectively.
Huge performance improvements for old and slow computers. Crafting a ladder now produces 2 ladders.
If lightning strikes a pig, it becomes a Zombie Pigman.
If lightning strikes a Creeper, it becomes electrified and will have a much more powerful explosion.
New settings in options:
Ability to change GUI size (Small, Normal, Large, Auto).
Advanced OpenGL (Occlusion Culling: doesn't render blocks that the player can't "see", helps performance in cards that support it).
Items can now be smelted with Saplings with the same smelting power as Sticks.
Dropped items in flowing water move faster than before.
Pigs that die by burning now drop cooked porkchops upon death.
Redstone dust can be placed on snow.
Wolves are more common, even in non-taiga/forest biomes.
Unarmed damage was increased from Half Heart.png to Heart.png.
You can now see names over the small spinning mobs inside the mob spawners by pressing F3. You have to be further than 5 blocks away from the spawner to see it.
Pressing tab will switch between input boxes. [/list]
И я ещё раз говорю, что оффициальный не модифицированный сервер 1.5_02 тоже летает по сравнению со 1.4. Может на гринкубс его ещё больше оптимизировали, но не надо присваивать себе слишком много. Нотч не забил на мультиплеер, иначе он не выпускал бы обновления для сервера.