Great article Steve - as usual - and good timing too, as there is a fair amount of discussion taking place on different approaches currently, including a mixture of the two articles you posted....

http://blogs.hbr.org/schrage/2012/05/projects-are-the-new-job-inter.html

From my experience, starting someone as a freelance contractor makes far more sense to me.

The number of times I have been hired on a short term contract (say 2 weeks) to do one thing, and then keep getting hired to do other things, is a far better corporate resourcing strategy - especially for fixed term project purposes - and taking into account Australian fulltime employment legislated requirements, checks & balances, etc.

It's far more efficient to get someone in quickly, initially on a short term contract, then take the relationship from there - and if it doesn't work out, it's also far easier to let them go (since a contract has an end date already) and I'm sure this may be the case in other countries too.