Here are some highly recommended resources on universalism and the Rob Bell controversy.
D. A. Carson’s session on universalism: http://tgc-audio.s3.amazonaws.com/2011-conference/sessioncarson_lovewins.mp3 (audio file)
A panel discussion moderated by Kevin DeYoung and including D. A. Carson, Tim Keller, Stephen Um, and Crawford Loritts: http://tgc-audio.s3.amazonaws.com/2011-conference/sessionpanel_lovewins.mp3 (audio file)
An article by Richard Bauckham on the history of universalism:
Bauckham summarizes the evidence in this way:
Until the nineteenth century almost all Christian theologians taught the reality of eternal torment in hell. Here and there, outside the theological mainstream, were some who believed that the wicked would be finally annihilated (in its commonest form. this is the doctrine of ‘conditional immortality’). Even fewer were the advocates of universal salvation, though these few included same major theologians of the early church. Eternal punishment was firmly asserted in official creeds and confessions of the churches. It must have seemed as indispensable a part of universal Christian belief as the doctrines of the Trinity and the incarnation. Since 1800 this situation has entirely changed, and no traditional Christian doctrine has been so widely abandoned as that of eternal punishment.
In other words, universalism is not a mainstream doctrine. It is a fringe doctrine at least until the 19th century (which, of course, was the time when virtually every orthodox doctrine—the Trinity, the Incarnation, substitutionary atonement, the inerrancy and authority of Scripture, etc.—came under attack).