An observant reader noticed the well-timed delivery of my recent World of Warcraft "Cheaters Survey" here. =]
The thing is, Blizzard is very predictable in regards to their ban waves.
They've been collecting user details for months, but wait until a certain time before banning all players at once. Banning still occurs on a regular monthly basis, mind you, but those are for high visibility infractions (e.g. botting that's noticeable by other players.) They want to keep their customers as happy as possible, so exploits/bots that are more visible are dealt with more expediently.
There's a significant amount of revenue to be made from banning accounts.. for one, the players purchase WoW and the expansion packs again, and they pay for a new subscription. It also looks good on paper because it counts as 2 "active subscriptions" since the banned account was already paid until the end of the month.
Blizzard will have large ban waves when revenue is typically lower than expected. They want to make sure their quarterly returns are as high as possible (to impress their shareholders), so bans typically take place during certain quarters.
This well-timed ban wave takes place right before their first quarter ending March 31, 2011. It's also taking place right before pay day. Coincidence? I don't think so. =]
(Note: It's not a very good sign that this took place so soon after Cataclysm sales either.)
As you're aware, Activision Blizzard prepared their shareholders during their last conference with the knowledge that they shouldn't expect any major game releases this year. With that in mind, they still need to drive revenue as best they can - meaning this year, you should expect either new paid services (or existing services with a twist like special discounts) and/or new virtual pets or other items that can be purchased. We might see some new merchandising, or other cool little things to increase revenue. You can also expect increased banning and re-activation of accounts. =]
This applies to all of Blizzard's games, not just World of Warcraft.
And if that wasn't interesting enough, look what Blizzard just posted (Source):
I'll take that as a confirmation.