I think those texts highlight a central problem which has been touched on by other posters - can you actually sit down in 2007 and describe a workable way for an entirely new world to operate?
Personally I don't think so. Nobody sat down a few hundred years ago and said "right, this is how I think things should work now, it's called capitalism" and everyone said "woah! dude! sweet!". It evolved over time because of specific social and economic conditions.
People who map out the future down to the last comma end up being tyrants, and surely that is people's biggest criticism of past attempts at communism?
The fundamental questions for me are:
a) Is capitalism the perfect way to organise the world - can it be improved on?
b) What is wrong with capitalism?
c) What are the sort of fundamental principles I would like a new world to operate under?
d) Is this possible?
We can have all the pipe dreams we want, and can even spend our lives looking back at past societies, or little examples of another world in more recent history, but this won't really amount to very much. At best, for me, all this is a signpost to something greater.
Really my day to day life has little space for such navel-gazing at present. It's all swallowed up with work and commuting and doing the housework and shopping.
One day things might be different, though...