I'm a fan of it as well. I'll love to go there to get out of the rain, use the restroom, download torrents, etc. It isn't a smart business move though since it encourages this kind of freeloader activity, and these kinds of activities will use up their limited space and make the environment less enjoyable for paying "customers" (since they want to define everybody as a customer, regardless of whether they actually get money from them or not). It's going to be an expensive PR gambit to reverse.
They must never have walked around on the street outside in Seattle, Portland, San Francisco, etc and noticed the rampant homelessness and addict population in those cities. Once word gets out that SBUX has this policy, what do they expect will happen?
I'm also a fan of this. I hate having to pay for a drink or something just to use a toilet or have somewhere to wait for a while.
I also dislike McDonald's being the only place open in the middle of the night. Every time I go in there late it's always full of drunk people.