GNU grep is still there because the regex implementation is not on par yet with the GNU version, once that is the case bsdgrep will become the default, especially once it is shown to at least reliably have a ports tree build work (on the build hosts).
bsddiff and bsdsort are available in the ports tree according to http://wiki.freebsd.org/SummerOfCode2008#head-860658a852d058...