Minecraft [official site] has added an awful lot over the years, but the fundamentals were mostly settled years ago. Now, Mojang are finally having a crack at improving its combat, and yesterday the developers released a test 'snapshot' build from version 1.9, showing their first crack at reworking fisticuffs. They're kicking it off by introducing an attacking charging system, which means an end to click-click-click-click-click-clicking.
The Snapshot 15w34a changelog explains that holding attack charges up a power meter to increase the damage dealt. This makes timing attacks and dodges far more important, making combat more dynamic and interesting. Reddit user 'Mr_Simba' notes that, under the new system, it can take 22 uncharged spammy iron sword hits to kill a zombie but only four charged hits.
It sounds like needing to charge and dodge might make combat far more interesting. I witnessed a Minecraft 'Hunger Games' PvP tournament at Eurogamer's Rezzed convention once, and was surprised to see it mostly involved folks chasing each other, swinging swords as fast as they could.
However, Mojang do say that the combat changes in this snapshot build "are completely not final nor balanced at all in the absolute slightest not even a little bit really honestly seriously." They say, "We welcome all feedback, but please remember that nothing is yet balanced and the mechanics themselves are subject to change and redesign." I wonder which fight-things they'll poke at next.
If you're more into building and programming than fighting, the snapshot also expands command blocks.
This is all experimental, so only download it if you're prepared for a little wonk. Mojang are evidently still a fair while off properly releasing version 1.9.