There has been quite a flurry of development revolving around the official ethernet shield recently. Here are what I consider a few of the more important changes.
Ethernet fixes – There are some connection issues with the ethernet library with regard to incomplete disconnects. Since the wiznet chip only supports 4 simultaneous connections, this manifests itself pretty quickly if you are trying to poll a server for changes. Etracer, from the arduino forums, found and fixed this problem and has released a new client.cpp as well as detailed the issues in a post to the arduino developers mailing list.
Another recent addition is Ben Combee’s Webduino library, which greatly simplifies processing html forms when using the arduino and ethernet shield as a web server. The library and basic examples are available at: http://code.google.com/p/webduino/
Bjoern Hartmann’s UDP library has also been used for a couple of recent projects including work on DNS/DHCP and fellow Infonomicon member Cynshard’s work on a NTP library. The NTP library is particularly useful since it can be combined with the software Date/Time library to have fairly accurate time without adding a hardware realtime clock to your project.
As you can see, there seems to be a lot of development activity ongoing for the official ethernet shield and since the addition of networking to the arduino greatly expands its possible uses, I think we’ll see even more. Please remember to thank these folks for their code and bugfix contributions…