A new open-source, fully web-based web conferencing tool is already in alpha stage right now for a limited number of testers.
Differently from what we have seen so far, DimDim, this is the new of this new web conferencing platform, is not going to be a geeks-only, hard to use gizmo with the label web conferencing stuck on it.
From both the feature list and the screenshots already available DimDim looks like a serious web conferencing platform, fully compliant with 2.0 requirements (web-based, cross-platform, nothing to install, low-cost/free, easy-to-use/no manual required) and with a professional, well designed interface.
Here more details:

Yesterday, D.D. Ganguly, CEO of DimDim and Prakash Khot CTO of DimDim gave a live presentation at Oscon 2006 introducing for the first time publicly this new web conferencing tool.

D.D. Ganguly, CEO of DimDim
DimDim official set of features includes the following:
DimDim is going to be made available in three different formats:
1) Hosted solution - for which, I imagine, users will have to pay a small price, based on usage
2) Open-Source Community - completely free
Recommended for: Developer, Highly Technical Enthusiast. Non-Critical Environments
3) Open-Source Enterprise - will have related costs though pricing and business model are not yet announced.
Recommended for: Corporations, Schools and Universities, Government, Not-For-Profits

Here is also the official time schedule for the release of DimDim to the public in the coming months:
Jul 28 2006 - Alpha release
Sep 1 2006 - Beta release Base version
Oct 1 2006 - Beta release Enterprise version
Nov 1 2006 - General Availability
Dec 1 2006 - General Availability Enterprise version
I can't wait to get my eyes and hands on DimDim to be able to report more closely on this new tool effective capabilities, performance and ease of use.
This is one to keep watching closely.
More info here:
DimDim Blog
DimDim Forum
DimDim team
DimDim is based in Boston USA, Ottawa Canada and Hyderabad India.
You can reach the smart team behind it by writing to:
info[at]dimdim.com