Most of the virus warnings and other chain types of emails I get are just plain text, and couldn't have this type of birus attachment. However, yes, if an email is in html format, it can have all sorts of nasty stuff attached or embedded.
Yes, absolutely. It annoys me that when you install Outlook or Outlook Express, the preview pane is activated by default. Something so dangerous should not even be included in the software, in my opinion, and absolutely not by default.