Because WebAnywhere is browser based, no software needs to be installed on a computer. That means that a user isn't tied in to a specific computer. It can be used at a friends house or in an internet cafe - on any computer, so long as it has a sound card.
There are similar screen reader programs out there already. But there's nothing wrong with a bit of choice.
WebAnywhere is scheduled for an alpha release - which is the earliest stage of development - at the end of May. In the meantime, the website has more information about what WebAnywhere can do.