It is awesome.
there are lots of changes to minecraft such as :
- trading with villagers (you use emeralds to trade with them)
- temples in the jungle and desert biomes (beware booby traps)
- gravel has a cooler look
- creative has a whole new inventory system (you can wear armour in creative too)
- you can use despensers in new ways
- people say that trees fall down when you chop them (but it doesn't work on my'n)
- you can host your own multiplayer servers for free
These are the biggest changes but there are lots of other little changes.