You can just export your db before installing and import the copy of db after. You can get some problems with customizations.
Remember that if installing the beta relase:
During the beta phase a minimal level of support will be given. We will provide answers to general setup questions, configuration problems and support for determining common problems mostly related to bugs. We will not support modifications, custom code/style additions or any users using the beta packages within a live environment.
For some support questions or bug reports we may ask you to re-install the beta, clean tables in the database, purge data or other actions which are not advised to do in a live environment. So please be aware that you are still on your own if you run the beta in such an environment.
Beginning with the release candidates full support will be given.
You´ll have to set the same tables prefix in the forums you could have before and after installing icy.
i think it won't work...but thanks anyway 
