Well, I just couldn't wait for vb3, so I installed this today and it's working GREAT on 2.2.8!!!
It was very easy to install, took only 10 minutes. It's a very solid hack, not alot of flaws in it! One of the flaws, as mentioned above, is the online.php file. If someone is viewing a thread in a private forum, someone can see them doing this on online.php and go to that thread. But luckily, you can disable online.php

I wouldn't use this hack if you have top secret information, as it's pretty easy to crack, but 99% of users won't beable to get in to the private forums, which is good enough for me!
Great hack afterburner and tyvm!!!