I've been trying to create a perfect thin client for quite some time and I was thrilled when raspy was announced. Specs fitted perfectly in my development of the super efficient client-server concept called Genie. I started developing Genie out of idea that SMB market and public service companies (especially schools, kindergartens, district departments etc...) needs better tools, but without the premium price tag. This was also my pain. Basically it is a complete IT environment with hardware, OSS software, services and server based desktops (similar to vmware view). However I got mine raspy almost a year later

About x2go/x2goclient:
x2go is a terminal service like system where users can have different configuration of the same system. It is similar to template VDI, but much more efficient, and above all free. It is loosely based on NX protocol. As I found out it overall performs better than the ubuntu LTSP. On local network one can achieve almost native like performance and the server is very scalable.
Prerequisites:
raspbian image
x2go server and x2goserver-session installed on server (follow guide on http://www.x2go.org, pretty straightforward)
root account enabled (sudo passwd)
Install:
There is a compressed file attached. Login as root and unzip it to /opt/thinclient and:
cp /opt/thinclient
...look at the sessions file and change parameters. more or less is self explanatory, important params is server address, user and session. however you can change that at anytime.
sudo sh ./thinclient_install
This will start the install script that would add repository, install x2goclient and set the startup script and seesion data for root user. However the installation will start the x2go client before the completion since the x2goclient session environment has to be set for root user. The client will not work without server counterpart. By default gnome environment is defined in a session, LXDE does not work with raspbian. Also I had mixed success with LDAP, it seems that LDAP should also be ldaps configured on the ldap server (636 port, out of the scope of this info).
After reboot raspy will boot into the thin client environment. This is readonly mode (session is defined in /root/.x2goclient/sessions). Upon first connect to server ssh handshake is done is written to the /root/.ssh/known-hosts file. If there is a problem you can always leave thin client environment and change session params. or even start x.
There is a modest wifi support embeded in the raspbian kernel, so usb wifi sticks should work.
Now you got a nice 25€ thin client!
Cheers!
martin
fasecor.com