I find it weird that they even offer a retail DVD anymore with this game. You have to get online to play in the first place, they pre-release the majority of the content to unlock at launch, and even if there was a day zero patch, disc owners would still have to download it. Just seems like a complete waste to release at retail unless I'm just underestimating the effect of the presence of boxes sitting on the shelf for people to see and want to play.
Boxed copies have their uses. First, exposure. Having it in the stores is in itself a form of PR. I realize it doesn't seem like it would be a big deal, but you're also likely a solid wow player and thus have picked cata clean of information months ago. There are many casuals who might not have played for awhile who Blizzard needs to show the game to.
Second, there are many people who have less than ideal internet connections or simply don't want to have to deal with long downloands. In this case, I prefer the box because I like that I'm getting a new DVD installer that is comprehensive through cataclysm. Times do come where I need to reinstall Wow, and its much quicker to just install the disc and then do a quick patch or two then to sit there and download many GB of data. If the digital download was cheaper I'd likely go that route, but for the exact same price I can also get the physical media. All things being equal, why not get the box in that case? I walked into walmart on my way to work this morning and picked up cata with no problems. I wouldn't have been able to play till I got home anyway. It's a win win for me.
I'm sure its the same for many people. Not everyone takes time off from work just to play a game lol