Tim Ferris is like most people on the internet with something to sell: they have some great ideas but you have to sift through some things. I don't think there's anything magical about the principles he espouses, but he does present some good ideas about how to implement them in a modern-day economy. It's tough to argue against the core principles that Ferris, and most business "self-help" guys espouse:
(1) Find something that inspires you
(2) Figure out a way to monetize it
(3) After establishing it on a smaller scale, outsource so you can scale up or continue working on new ideas.
A bit of advice my father gave me on running my own business was: "try to spend as much time working ON your business as working FOR your business." Meaning, if you are spending a lot of your time/energy on doing rote, unskilled labor for you business, it is going to be tough to make it grow. Train somebody to be able to do that, so you can keep focusing on the things that will grow your business and/or make your product better.
A lot of this stuff is the way many businesses (especially non-union physical labor jobs) have operated for years; just repackaged and branded with this jetsetting "lifestyle" stuff to sucker in the Entourage-generation who wants to live the baller lifestyle while not having to work for it.
Think about what you would do if you had a landscaping company:
(1) You would start with yourself, maybe one helper and one truck to service the couple of initial clients.
(2) While you are doing the labor yourself, you would also be working off-times to try to get a couple of new contracts. You would also be training your helper and gradually giving him more and more responsibilities.
(3) You get a couple more contracts and you make the jump to two trucks. You run one while your guy runs the other. You train another guy to run the second truck and now you can focus full-time on bringing in new clients, etc.
The most powerful thing that I've gotten out of the 4-Hour Work Week culture is to think of yourself as a corporation; ie, you are your own company. Try to spend less time getting bogged down in the grunt work and more time working hard to create new opportunities. I think a lot of people (encouraged by the "lifestyle" blogs, etc.) seem to think this means less work, but in reality, it's just different.