There are four major providers of cable Internet access, and several smaller players, serving a smattering of locales. Chances that your area is covered today are not good. In order to offer Internet access via the same wire that your television signals travel on, your cable company allocates part of its bandwidth, enough to carry a TV channel or two, to Internet traffic. The cable company broadcasts incoming Internet packets to everyone, but unlike a T.V. signal, which can be seen by anyone who is tuned to that channel, each Internet packet has an address which assures only its intended recipient will see it. Cable modems can theoretically deliver data at up to 350 times the speed of a 28.8 modem, but you won't have all that speed to yourself.
Cable access is a shared resource.
Subscribers share the bandwidth with the cable customers on several nearby blocks. 10 MBPS is more than enough bandwidth to go around. Sending data over cable isn't as easy as receiving it. Due to technical limitations, most cable Internet services don't let you send data via cable. So, hybrid systems in which incoming data comes via cable but outgoing data travels on your phone line with a traditional modem, are most common.