Ugh, I understand that it can be useful for some people, but I find natural language parsing of calendar events intrusive and annoying.

99% of the time it ends up parsing a field incorrectly, and if I wanted to set a field it's on the form anyway, so why bother? In this case, why parse out an email address and send them an invite when there's an "invite" text box on the same page?

If the only way to set the time, date and invite list was to have the subject line get parsed, it would be obvious that this sort of thing will occur.

Honestly, to me this is a solution in search of a problem.