Is there any benefit to picking up an Airport Extreme since it will just have to plug into my 2wire anyway?
What are the requirements for your wireless network?
The 2-Wire is limited to "g" wireless speeds (54 Mbps). An AirPort Extreme is much faster at "n" speeds of 130 Mbps, or up to 300 Mbps if you are using the 5 GHz band.
So any files transfers/copies over an AirPort Extreme network will be much faster. Is this something that you need?
The AirPort Extreme has a USB port that will allow a printer and/or hard drive to be connected and accessed by wireless from any computer on your network. Is this something that you need?
The AirPort Extreme's wireless network can be extended for greater wireless coverage if you add another AirPort Extreme or AirPort Express. Is this something that you need?
If you don't need any of the items mentioned above, then you probably do not need an AirPort Extreme.