Tor Browser 4.5 now has a security slider that you can use to disable browser features, such as JavaScript, as a trade-off between security and usability. The security slider is set to low by default to provide the same level of security as previous versions and the most usable experience.

We disabled in Tails the new circuit view of Tor Browser 4.5 for security reasons. You can still use the network map of Vidalia to inspect your circuits.