It's out now
The XenForo beta release is now available, at the $100 sale price for the next 24 hours. Despite what they say in terms of the timing not being related, making a public announcement about the suit at 5:29pm the day before XenForo was meant to go on sale can't reasonably be seen as anything but an attack on XenForo.
36 hours late (or so), I'm glad that XenForo's now out and I can remove vBulletin from my websites - their vBulletinv4 software is a joke in terms of features and stability (never mind the pricing changes!). They seem to believe in putting their time, money and effort into trying to take down XenForo rather than improving their own software. A real shame but a perfect example of what happens when a big corporation doesn't really understand what it is buying when they acquired Jelsoft/vBulletin.