Scribble
First Post
If I were them, I would do this through a separate "Power Builder" tool, which would have the ability to export the finished power to the Character Builder, rather than including the ability to build custom powers into the CB directly.
But then, as I mentioned on another thread, I think the next step for the DDI is to allow users to 'open' their creations (monsters, powers, adventures, etc) for other people to use. That way, they get a DDI that is constantly increasing in value for minimal development effort - all they would need is an editorial team to take the best of the community work, apply errata, and promote it to official status.
I think they will do exactly that in the adventure tools. The DM will get a custom power/feat/item builder.
My guess is they plan to link all of the tools together, so the DM gets to choose what options are available for a campaign, as well as add any houserules, and the players will see his campaign show up as one of the options like the current ones show up now (Dark Sun, Forgotten Realms, Encounters, etc...)
Then all that stuff gets to be imported into the game table.