There's a reason, of course -- the current e-ink technology is simply not built for web browsing -- the page refreshes a lot during scrolling, images don't look great and in the case of the Kobo, there's no pinch-to-zoom, so you've got to rely on an ever-present slider on the bottom to make things larger.
ENGADGET: Kobo Glo review: another illuminated e-reader lights up the market