Gaming itself can be a simultaneous bonding activity and point of division. Altogether, though, it's just proof that human nature strikes us where we least expect it. Sometimes that escapism really is just a good break from reality. Granted, it's a break that can also come with lounging on the couch with a movie in the DVD. The draw of MMOs is they're always there. 24/7, there's someone out there that you can hop on and run off with.
The key to mingling with a fanatic is finding a homeostasis. If the wife is playing too much WoW for your comfort, then ask how you could ask her how she can be encouraged to spend more time with you. If you feel you're shorting her of her own time, then adjust plans so that she can enjoy herself in that way. Without finding the middle-ground, though, someone is going to be miserable.
Sometimes, the MMO just appears in lieu of other plans. When you compare the chore of doing dishes with WoW, then the latter will win-out without fail. If you plan an outing to the park for a picnic, it doesn't strike me as too likely that the level 80 instance that was about to be run would win out over quality time. Though if it seems to bother you as much as the article suggests, then the gap's going to grow without some input.
Marriage is a fanaticism of its own, and needs just as much input as any MMO. If not more-so.