Hugh has a great email interview with Seth Godin. There is a particularly important quote that start up types should remember, possibly make a 50x50 foot poster of this, as you are going through product design and assumptions about your audience.
"ANSWER: I'm astonished at how long it takes an idea to filter from the early adopters to the masses. What sort of person just read the Da Vinci Code or just discovered the iPod? I was standing in a nice store in a nice suburb and heard one 25 year old explain to a 30 year old what gmail was... it's so easy to assume that everyone already gets it"
As a bonus, you can read Fred Wilson's post about finally switching to a newsreader. Again, keep Fred and Seth's comments in mind when you are making assumptions about your audience and the potential habits you are trying to change, break or just slightly modify.
Enjoy your weekend, folks.