The image on the left is from the EU Battle.net post, and the image on the right is from the US Battle.net post. (Thanks qmk and rpgguy.)
Since the cache from the original US post is gone, and Blizzard had made modifications to their website to prevent archiving (e.g. change detection websites, archive.org, etc.), I don't have a copy of the original US one. Luckily, some individuals copied and pasted the original post which confirm that these changes did indeed happen within the US post.
So.. notice something missing?
"Download the digital version via Battle.net for free when the game launches early next year" has instead been replaced with "Download the digital version via Battle.net for free when the game launches."
As of right now, the EU post hasn't changed, and this could just be a result of those users who want to cancel their WOW Annual Pass by claiming that Blizzard did not uphold their end of the contract since they explicitly stated "Early 2012" or "Early Next Year." If that's the case; not cool.
Users are also reporting that other WOW Annual Pass verbiage has been modified to remove the "Early 2012" mentions. If you look under all of the WOW Annual Pass Support Articles, you'll see that they have modification dates of January 16 or January 17.
While I was doing some digging around for PayPal and Battle.net Balance updates a while back, I also noticed the same "Updated On: Jan 16 or Jan 17" dates. I just ignored them, though, because I couldn't view the old cache. Surprisingly, when Blizzard makes changes they are updated almost immediately by Google. Same thing with the latest WOW Annual Pass changes. Even when pages or forum threads are deleted, I see that Blizzard leaves some of them Google cached and others not, so I imagine they have some measure of control over this.
This article update might not mean anything at all, though, but we'll know for sure over the next two weeks (see my post from earlier today.)