This exports all your scheduled items in a single, iCalendar or vCalendar file. You may then import this file into any iCalendar-compliant system such as OutlookTM, then subsequently synch to your PDA.

Oh super, Outlook. That’s great for the PC manager who gets sent to MacWorld to see what this Mac hullaballoo is all about, but it’s useless for 95% of MacWorld’s attendees. Are you serious BDMetrics?

Update:
OK After spending way too long looking at Apple’s iCal specs and messing with the tags and blogging the whole thing (and using ♥ in my URL, so the thing broke on every other browser besides Safari!) I have the solution. But first the reason they don’t work:

HA! Of course a spec written in 1998 by an MS employee calls for CRLF line endings! Of course, it makes sense now!

OK so here’s the code. Get thee to a Terminal, cd to where your ics file is, and copy and paste following onto one line, and you’ll be good to go
perl -p -e 's/VERSION:1.0/VERSION:2.0/g' ShowCalendar.ics | perl -p -e 's/(\r\n|\n|\r)/\r\n/g' > newShowCalendar.ics