Don't worry, I am not going to spoil anything if you haven't seen it yet. But, we did go see the epic conclusion, and it was wonderfully done. Lots of action sequences and fun new spells that we don't see in the other movies.
If you haven't seen the other ones, it would be totally worth it to rent them all and have a movie marathon weekend before going off to see the last one. At the very least, you need to watch Deathly Hallows part 1.
More than anything, what amazes me about this series is Rowling's ability to touch on themes that touch so many people, and touch us so deeply that it shattered box office records worldwide. Perseverance, determination, bravery, friendship, love, support, identity, good vs. evil...themes that touch us all portrayed in a whole new world.
Plus her ability to tie together everything, connecting each movie, each character, each subplot is mind boggling. I am also shocked that she has been writing new material that they have been waiting to release until this last Potter movie came out. Talk about setting the bar high!