Do you mean you cannot even see the wave logo and link to log in on the developer sandbox. You cannot see a wave until you have a login anway just now. Something like this would show up if you logged in: http://openvce.net/wave-example
But it really should just be the wave iitself, which was displayed before. It needs the code adjusting, as we are getting the whole Wave user area. it also need the GUI colours amending to be OpenVCE.net style. This tutorial is what I followed to set it up: http://code.google.com/apis/wave/embed/guide.html
The wave was working a few weeks ago, but seems to be failing again. Now the sandbox login asks you to install the "Google Chrome Frame" for Internet Explorer. Which does lets you view a wave in a separate window after sandbox login. But the wave does not show in the frame within OpenVCE.net at http://openvce.net/wave It does work in Firefox.
The wave is again operational. And the "OpenVCE Wave" is now a public wave on the main Google Wave setup.