Turns out that the "developer preview" of Google's latest creation, Google Wave, is not as open as one would expect, with the preview only being open to attendees of Google's I/O conference.
But there is another way to see it in action: as an attendee of Google's upcoming developer day conferences, one of which will be held in Sydney, where you will be able to gain access to the system before consumers get full access later in the year.
On the question of why not go live now with Google Wave, Jens and Lars Rasmussen cited that it is not ready for the general population. Wave itself is best viewed in WebKit-based browsers or Firefox with Opera support still coming together. For Internet Explorer, Lars Rasmussen said that there will be no IE6 support for Wave, but intends to target IE7 and above.
The reason for this is due to the lack of HTML 5 support for Internet Explorer 6, in particular, the use of web workers which are analogous to threading a web application.
For people that are worried that Google Wave is the next incarnation of Google Trapper Keeper, the servers that the communication is hosted upon do not necessarily have to be Google's. If you are interested in the protocol itself and are crazy enough to want to create an implementation of it, information can be found on the wave protocol site.
And if you want to try to explain what Google Wave is to others, so far I've managed to restrict the description down to a "hosted communication and decision engine".
I'm sure there is a more apt and succinct description for it, if you have an idea post it below in the talkback.