Release Notes: This release updates the addresses for two of the eight directory authorities, fixes some potential anonymity and security issues, and fixes several crash bugs. Tor 0.2.1.x has reached its end-of-life. Those Tor versions have many known flaws, and nobody should be using them. You should upgrade. If you're using a Linux or BSD distribution and its packages are obsolete, stop using those packages and upgrade anyway.
Release Notes: This release fixes a crash bug when you're accessing many hidden services at once, prepares for more performance improvements, and fixes a bunch of smaller bugs.