I wouldn't say WotC is trying to use 4E to combat WoW, but they do compete for some of the same income stream. I agree with posters above that WotC has got to find a way to get players to pay that monthly fee that any business manager would love to get. That is the business aspect. WotC is a business, and its product--in this case 4E--has to make money.
At the same time, from a play perspective, D&D is a much different game. I actually think 3e & 3.5 model a computer game in many respects. I say that not as a computer gamer; I don't play MMORPGs, so I don't have a basis for true comparison. But I will echo the sentiment of the poster above who felt like a CPU just trying to crunch all the numbers in combat. This is the key difference in these 2 types of game. One has no computer to do all the math.
The challenge for WotC is to make 4E significantly easier to run while delivering relevant material via the digital initiative. I haven't heard those details yet. The options for players can be virutally unlimted. It is relatively easy to keep track of one character as a player. Applying those some complexities to the foes is what can make DMing so onerous. Foes need to be almost drag & drop, fire & forget, and plug & play. It would be nice if the digital initiative provided such foes, but it doesn't sound like it will. It sounds more like there will be tools to create adventures, but the DM will still have to create the module. I would find it more helpful to have a digital Dungeon.