Does anything good happen at 50?? What should I be doing when I hit 50?

Yes. You will now get absolutley dominated in bg's by all the lv 58-59's that have their tier one blues, and lvling will take forever.

Seriously though, 50+ is fun. However unless you are in a guild with lots of people your same lvl, finding groups for Sunken Temple (lv 50-55) and BRD (54-60), not to mention LBRS and UBRS is going to be tough. At least on my server. There are good places to grind and quest (un'goro, wpl, felwood) that will net some good xp to help the lvls go by quicker.

50 isn't anywhere near as exciting as 40, other than being able to wear some killer gear (ironfeather / warbear sets).

Look at my guide for Sunken Temple in the quest forums. Druid loot galore.