Huh?!
Why give away any traffic and potentially let others leach off of your site. Doesn't seem very wise to save $8.95 only to insure a headache down the road.
Don't you think that in a consumer's mind, there could be some confusion, especially if the owner of the .net, etc., puts up a legitimate site in competition with the .com, etc.
Why wouldn't you want to protect your brand across at least the major .tlds.
No reason to cry or complain about anyone snatching the .net, and how improper it is, when you don't have the foresight to register it WHEN ITS AVAILABLE!