Can someone explain what this is?

What bug tracker are you talking about?
Will people be able to submit new bugs, or only staff?
Can we use paid subscription?
Can we use it as a todo list too?

Will you buy it?

1- vBulletin Project Tools (http://www.vbulletin.com/forum/showthread.php?t=224441)will be tools used on vBulletin forums. vBulletin developers are merging the current vBulletin bug tracker with an internal feature tracker, that will result in a multi-functional project tool to be used on vBulletin forums to report bugs, as well as manage software development.
2- The bug tracker (http://www.vbulletin.com/forum/bugs36.php)is in current use on the vBulletin forums.
3- It has not been announced if board members can also report bugs, it is very likely both forum staff and members can report bugs.
4- Using paid subscription as a feature is not currently known.
5- Whether or not you can use it as a todo list is not currently known, it may be a key feature, however features of the vBulletin Project Tools have not been released.

I will likely be purchasing both the new blog software, and vBulletin Project tools..

Update on vBulletin Project Tools (http://www.vbulletin-tutorials.com/showthread.php?p=159101#post159101)- March 30/07