I think some people here are being a bit harsh.
I've browsed on 192, 384, 4096, 7.2 and faster and on pc's and different isp's in 4 different countries. If one excludes downloading, it's my experience that browsing at any of those different speeds is pretty much the same give or take a second or two here and there. On the faster connections, you still find yourself waiting for factors such as the server at the other end to respond, the congestion at various points along your datas journey, etc.
Sure, downloading on a 192 kbps line can be an exercise in patience, but hey - not everyone wants to download stuff. Their windows and AV and Adobe updates they can leave for when they're not using their PC's.
If they can have an always on connection (ie: ADSL as opposed to the dreaded dial-up) where they can leave their pc's on and connected so updates can carry on at their own pace, their Skype can stay connected and they can see who's online, their mail prog checks for their mail every half an hour, etc, etc, and know that all this they can have for a set monthly fee with no 'bill-shock' at the end of the month then I think it's a winner.
Personally, I don't think the product would be my first choice, but I definitely believe there's a market for it.