Well, let's take a look at one of the primary sources of news during the war; the newspaper. Taking a random New York Times edition from 1944 (October 10th, if it matters (link, paywall)): the headline refers to three articles, one each about the Western and Eastern fronts in Europe, and one about Churchill and Stalin meeting. Also on the front page are articles about a bombardment in the Pacific, a Soviet newspaper accusing the Pope of favoring a soft peace, some Germans surrendering in Finland, a change in the draft categories, plans for managing demobilization of veterans, and the formation of the United Nations. There's also a "War News Summarized" section. There are only three front-page pieces unrelated to the war- a public wake for Wendell Willkie, the Cardinals winning the World Series, and the start of the opera season. In the index, there are 54 articles tagged "World War II", and upon looking through the pages, that may be an understatement- it's hard to find an article in the main news section that isn't related to the war. The War Production Board decides not to purchase South American wool, the IRS makes gold braid on officer uniforms tax-deductible, American engineers make a trolley car bomb and send it hurtling through the streets of Aachen (???)... And that's in addition to the couple dozen articles about the actual fighting. Obviously the NYTimes isn't perfectly representative of what an average American would be reading, but it's probably safe to say that news of the war was very widespread.

For perspective, around 12% of the U.S. population was in uniformed service during the war, compared to about half a percent today. And that doesn't count those engaged in war production. To contrast, according to the most recent info I can find (March '17), there's in the ballpark of just 10,000 soldiers deployed to Syria and Iraq, and not many of those are directly engaged in ground combat. In terms of how much the war against ISIS affects the average American, compared to WWII, it doesn't even register as a blip.