Yes, pretty handy. You can use your phone to get the internet on your laptop. I like this because hopefully I will no longer be at the mercy of Starbux to get connection when I'm out. I can use my computer in hotels, etc...
People carry around both an iPhone and a laptop? Why? I can do 98% of what I can on my laptop on my iPhone and the few things I can't do I just remote into my desktop for.
I never really see the need to carry a notebook around, so AT&T's lack of tethering from the gate just doesn't seem to be a big deal in my opinion.