Haha, that was a pretty funny video (but honestly, I wasn't referring to anything porn-related). I'm signed up with a service called deathswitch.com to send my brother and his wife part of my master LP password (the other half will be written down for them. t's not absolutely necessary that they have access to my LastPass account, it'll just make things much easier for them.). Right now I'm just on the free account, which sends out one email to one recipient, but soon I'll be signing up for the paid version which costs $20/yr. and lets you send out something like 30 messages to 10 recipients. So if you were to offer some sort of similar service I'd definitely be interested, and would certainly consider a paid upgrade for it. I think as sites like deathswitch and Legacy Locker become more well-known, more people will become interested as well.
But anyway, besides the idea of maybe having a couple accounts that I don't want them to access, I think the second/different password option would in general also add another layer of security to LastPass.