Shedor wrote: Will all the "pluggings" that I have installed that was for 1.9.1 work under an upgraded 2.0 Beta3?
What will become much better? Will there be a chat possibility for registered users in this version and in general would you advice me to install it at this state? 
First feedback - CB 2.0 BETA 3 is still a beta release and should not be used on production sites.
This has been clearly stated (a number of times in the announcement) and repeated again here.
The beta releases are meant to be used in test environments in order to test and give feedback in order to fix and improve.
All existing CB plugins will most likely have some issues with CB 2.0.
If you install CB 2.0 B3 over a CB 1.9.1 TEST site with existing CB plugins, the upgrade of CB will take place and the plugins will have a notice in the CB Plugin manager that they are not compatible with the CB version installed.
Some may work, some may have issues.
As Kyle said, CB 2.0 release will be followed by new releases of all CB add-ons.
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