WIFI is great to daily load Newspapers, read RSS, etc...
Moreover, as someone said, it makes anyone without a computer
able to buy ebooks! Grandmothers, etc... of course you still need an
internet connexion but you can for instance use free starbuck/mcdo
And btw, I don't think it costs more than 10-15$ by units to include a
wifi 802.11g chip. Maybe you think it's expensive because of the iRex,
but remember the most expensive part of it is the large touchscreen e-ink
display, NOT the wifi chip!