Arduino ethernet to digital pins

Well there is a possibility that I'm just blind, however I have not been able to find an answer to this issue. Is it possible to access the serial pins or any other digital pins through the ethernet shield as a virtual serialport? I'm helping someone setup a remote control paintball turret. It currently is controlled from a vb.net application with a joystick, through the serial port. Serial port -> Xbee -> Xbee -> Arduino. There is video feedback via WIFI from a web cam. If possible, I'd like to eliminate the xbee and just go through wifi. Computer -> Wifi Router-> Arduino Ethernet shield. It would be very easy to just access it as a virtual serial port, that way I wouldn't have to worry about rewriting the vb.net code.

Any thoughts?

Thanx

Is it possible to access the serial pins or any other digital pins through the ethernet shield as a virtual serialport?

Access pins, and reading serial data, as both possible.

It would be very easy to just access it as a virtual serial port, that way I wouldn't have to worry about rewriting the vb.net code.

Start worrying. The Ethernet shield is not an extension of the serial port.

The Arduino with Ethernet shield is either a client, periodically polling a server for information, or it is a server, periodically responding to GET requests.

You most likely want the Arduino to act as a server, responding to GET requests. The GET request will convey additional information that tells the Arduino what to actually do,

That is going to require a major rewrite of the VB application.

If possible, I'd like to eliminate the xbee and just go through wifi. Computer -> Wifi Router-> Arduino Ethernet shield. It would be very easy to just access it as a virtual serial port, that way I wouldn't have to worry about rewriting the vb.net code.

As long as the the joystick is connected to the computer, the computer will have to be running some type of program to support the activity. If you want to use the ethernet module for lan/wan connections, the probable communication choises would be http, telnet, and UDP protocol. You would need to develop the appropriate application on the pc to support these. The arduino with an ethernet shield would have a server application to respond to the commands from the pc.