Battle of the MMOGs?

With "MMOGs," I'm referring to massively multiplayer online games, and the "battle" that's shaping up is between 10 million-member World of Warcraft and just-launched Warhammer Online: Age of Reckoning. USATODAY says the newcomer might "siphon off" some of WoW's success, but there's probably room - if not in players' schedules, then - in the huge and growing MMOG market for a lot of new games. A few facts about MMOGs in general and WoW in particular: The US market alone (WoW has players in many countries) is "expected to amount to about $800 million this year," up from $700 million last year and $332 million in 2004," USATODAY reports, citing data from market researcher DFC Intelligence. WoW players spend $40-60 up front to buy the game's software, then $15/month to play. Warhammer is published by Electronic Arts and was created by Mythic Entertainment. [See also this item about when WoW passed the 10 million mark (about a quarter of those players are in North America).]