USB flash drives don't tend to be reliable enough for me to put anything important on anyway, so I need a port for that once in a blue moon. If I want to send someone else files, I'll AirDrop it 5% of the time, or Dropbox it the other 95%.
I think I've plugged in my iPhone and iPad together once, to see if iTunes would sync both, but I never need to sync both. Hell, I rarely need to sync either with iCloud and WiFi sync.
My external HD plugs in over Firewire, because backing up 200gb of data over USB2 is a total joke.
My "go everywhere" camera uses SD cards, so I never need to bring a card reader when I travel. My DSLR uses CF cards, so I only need a USB port for when I use that.
My home printer is shared over the network, so it sits connected to a desktop downstairs. It's cheaper than everyone in the house buying their own printer.
So my only normal USB usage comes from my external keyboard/mouse (one port). But if I had 3 ports, then I would still have 2 ports open to look more professional with!
If you think thunderbolt peripheral prices are bad in the states, they're insane in australia.
A sonnet PCI box is $799. with nothing in it (add north of $200 for a GPU worth anything). The pro version is something like $999.
I recently looked into it, with a view to getting rid of my MBP and running an air + Discrete GPU in a PCI expansion box.
I could buy a gaming PC PLUS an MBA for the cost of it all.
While I agree that TB devices are definitely expensive, things like a PCI expansion are entirely made possible by TB. This isn't exactly a case where you could buy a cheaper, USB3 version (if only you had more USB ports, or something).
