Here is a nifty resource for looking at the development of virtual worlds over time. It is created at the website Dipity which is an aggregator of content with a twist, the twist is that the content can have meta-data added to it to add meaning and to display it visually within a timeline, a list or a flipbook.
So one can gather data from all over the web and place it into a neat timeline or even a visual flipbook.(as has been done on a number of topics including virtual worlds and H1N1).
Here is an interactive widget showing virtual worlds time line from Dipity.
It is a great resource, the only thing I might add to the timeline is some corporate-based virtual news such as:
Qwaq Changing It's Name to Teleplace (Here is the Teleplace web site)and other corporate 3D Happenings.
Catalog of Recommended Books, Games and Gadgets
Recommended Games and Gadgets