There is no point releasing hacks for a beta product IMO, there are going to be code changes and whatever before the RC is released so any hacks you create now either may not work on the RC or will use code which is out dated. Not very hard to understand, and I would feel the same way about any other beta product.
And obviously vBulletin.org/.com want to be running their own software on their site, if they choose to install any added extra's themselves it's up to them! You can do the same to your vB3 board, no one has ever said they _have_ to share any code they have created above the actual vBulletin product.