"It is strongly recommended for anyone running version 8.0 and above, and fixes a number of issues with 8.2. It also adds searching to Express Objects and more!"
That's what the original blog article over at concrete5.org mentions. The biggest issue I was having from upgrading 8.1.0 to 8.2.0 was the broken pagination everywhere. People couldn't navigate pages anymore - this was a serious issue if it was working before.
Reading the full bug fixes list, it seems like we should've all skipped version 8.2.0 and go to this one! Lots of new things to try out.