deb.torproject.org currently contains 0.2.4.19-1~d79.jessie+1.
When will Tor 0.2.4 migrate into sid and/or testing?
When exactly, is never known with Debian project. You can watch the Debian Package Tracking System for news and the todo of the package. If you want to make the package enter early, check the TODO and look what you do to help.
This is the Tor package page: http://packages.qa.debian.org/t/tor.html