Is it just me or there are actually icons in FontAwesome 3.x.x that are missing from FontAwesome 4.0.0? If so, this definitely makes FontAwesome much less awesome for me...
For example, I can't seem to find the equivalent to icon-remove (there is no fa-remove, or fa-delete as far as I can tell).
Having to rename all icon references in my application is annoying enough. Not being able to reproduce what was possible in 3.0 is really, really bad.
Not being able to access v3.x cheatsheet and other documentation any more: unacceptable!
fa-times? - Michał Rybak