Waiting for "someday" will leave you on your deathbed wondering why you didn't just rearrange your priorities and enjoy the time you had, instead of waiting for a "better" time to come along...
I saw a picture of the bed about a month ago and thought it was really neat...and then, like Paul, I was trying to figure out if it was worth the space savings if you had to store the mattress somewhere. I really, really like the the bed. Great innovative idea.
The link (which may have been lost in comparison to the photo) says the developer uses it for medieval re-enactment gatherings. He uses a futon mattress, which I presume would roll up into a neat package. I think it's IKEA that sells some foam mattresses that come in a tidy roll.
He also says he worked through a lot of prototypes to get it to work right, so I'd suggest getting the article with the measured drawings.