I also support Khaled's changes to xetex; I only tested it few months ago and if the issues I reported are fixed now, then it is good. And since when LaTeX has a package/ or test files that uses \beginL \endL? All I remember is that there are only babel's rlbabel.def file and then arabicore package but these packages themselves contain bugs (irrelevant to xetex). bidi is the only big package that uses e-tex bidirectional algorithm for right to left typesetting. With the new changes of xetex, bidi package needs to be written from scrtach but I have no complain against it; the news that the \special and other issues fixed in xetex makes me so happy that I will not complain about changes. I am grateful to Khaled for fixing them.
-------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex