First of all, I'm aware that this is probably not the right forum, but where else should someone post questions about hacking vbulletin? (Since its not a template issue).
Anyhow, move it if you like.

On topic:

init.php has been completely revised, I now have no clue where I should place my constants now?
Perhaps it should still be in init.php, but if so, please give me an example on how to do this.

Thanks!

Edit, I'm talking about 3.5.beta in case you are confused. ;)