This could get interesting. The Guardian blog pulls in Don Norman and Joel Spolsky. On the other side of the ring we have 37signals’s entire business model and possibly even Google if you squint enough.
My hunch is that 37signals et al are on to something. They are trying to sell the idea that less features = more usability. The choice of price points is critical to this approach working. Higher priced products make people nervous about their investment and they will try and protect themselves by buying as many features as they can.
With cheaper products, you end up dealing with a more rational consumer. You might then be able to sell them what they need instead of what they think they might need.
UPDATE: Nick Bradbury joins in: http://nick.typepad.com/blog/2006/12/simplicity_aint.html