BF1942 and WWII Online are totally different games, there is no way to compare them. You don't play WWII Online for the great graphics or the fast action. You go there for realism and immersion as Morrigan said before.
The huge amount of players playing at once, the gigantic world map, the epic battles that can take days. It makes you feel like your just a small person in this big working army but at the same time you feel like you really can make a difference.
All in all you have to be for it, but don't be misjudged by first impressions. This is a great game and I take over BF1942 anytime (but that's just me).

Great game. Update releases every 6-8 wks. Total immersion in all areas. Learning curve is steep but hook up with others in game and its a blast. Air war, ground war & naval all interacting on the same real time plane. Minor bugs & tweaks needed but not bothersome. Great interaction between the developers and the playerbase. Totally recommended!!

How would this compare to, say, BF1942 with or without the Desert Combat mod? Both of those games need iron, but the last time I tried WW2Online, the interface was pretty dismal (and ported PC games generally already have awful interfaces to begin with)

if you want realism in combat and immersion as opposed to stunnin graphics, this game is great. requires some serious iron though.