You can use it but not all of its function will be available. If you plan to use it to share your cable Internet, then it can't.
The 2Wire is a 4-in-one device comprising of adsl modem, a router, a switch and an access point. Of the 4, you can no longer use it an adsl modem as it won't work with your cable. You also can no longer use the the router function as it work between the adsl interface and the ethernet (switch) interface. Since you're not using the adsl interface, then there's no routing. That also means no NAT hence no sharing.
So what it can function now is as a switch and an access point. To share your cable, you still need a router, although need not be wireless, to share your internet. So what it should look like then is as below
cable modem <> ethernet router <> 2 wire
This way, you will have wireless networking without having to buy another wireless access point or router.
All you have to do is the turn off the DHCP function on the 2wire by setting a static IP on it as shown below.