This is how it will appear in the inbox of an unsuspecting human:
Now the attachment is hosted on Google docs, from which you would need to download and run it.
I know, I know, It isn't really an "evil attachment" it is just a link to an executable...
but, it is a google calendar invite hosting a link to an executable file on google docs.
now I know a few people who aren't as paranoid as me and would trust google hosted files more then just a random hosted file on some unknown server, but then again, that is just me :)
Food for thought.