I think this is a good article to describe how OS X will be all the more powerful as people take more advantage of the Unix base. As for the Tcl references, I wanted to make some small comments / corrections. The reference to http://www.scriptics.com/ for Tcl should be http://www.tcl-tk.net/ or http://tcl.sourceforge.net/. www.scriptics.com now is a direct DNS pointer to www.tcl-tk.net, but the tcl-tk reference is better in the long run.
I am curious why the author needed 8.4a2 to build Expect with (since the default tclsh on OS X is 8.3.x, IIRC). Expect, being a good Unix Tcl extension, should have built with the stock tclsh on the Mac.
The choice of ftp perhaps wasn't ideal to showcase Expect, since that can be done with the pure Tcl ftp module in tcllib http://tcllib.sourceforge.net/), but Expect is still a rather formidable extension. Now that the Mac has a Unix base, that opens up a lot of control of the rest of the world via Expect from the Mac.
The closing remarks about complementing Perl, which would be used on the web server, seem ... unimaginative to me. After all, Tcl can be a full web server, and tclhttpd (http://tclhttpd.sf.net/), written completely in Tcl, is reported to work just fine on OS X (that's the same web server running http://www.tcl-tk.net/).
Jeff Hobbs - Tcl Core Release Manager