Upgrading 6.X

No upgrade option yet as it is the first BETA, maybe by ALPHA there will be an upgrade path.  The BETA is not for production use.

if and when there is an upgrade path, ...

how easy / hassle free will it be to upgrade?

what typical impact areas can I expect? (There are normally some!)

for example, will this upgrade impact modules that I have bought from Dolphin developers? ie. render them useless?

Thanks.

There is no upgrade , this version don't use it for a production site!!!

Once the upgrade path is delivered, more than likely any modules that were made specifically for a D6 version will either not work, or the developer will release a new version of the module for D7, you would probably have to contact the developer to find out what there intentions are.  Or to even find out if the modules were tested and working with D7.