I would like to know the same. I've been sort of charting this practice ever since I really got into anime in mid-200ish. I think that, sociologically speaking, those practices wouldn't cross over on a cultural level amongst American anime fans.
For one thing, the language we speak is a construct of expressions that come from many different sources. The sentence I just wrote has roots in Greek, Latin, Germanic, and Hebraic linguistics. Phrases like "baka" and other Japanese idiomatic terms might cross over into the vernacular, but into the language? That's another story.
Cultural practices are a whole other matter. Over time, cultural practices can make their way into the shared experience of a nation, a people, etc. They have to happen on such a scale as to create a long-term, lasting effect on the culture around them to be adopted. In terms of American otaku, there's an air of uniqueness to the Japanese aspects of anime that are absorbed, and with the level of most otaku, they're abosorbed without knowing the significance, origin, or meaning of the act within its originating culture. How many fangirls can tell you about how Valentine's Day was co-opted by manufacturing conglomerates in Japan to promote domestic chocolate production and consumption? How many can then tell you how White Day was created (Like a "Hallmark holiday") to encourage further development? Also, given the nature of the submissive female in Japanese culture, such practices probably wouldn't cross over as well in the US.
I think that the culture will spread and intensify within otaku. What will be interesting is the next five, ten, fifteen years. These young otaku are going to grow up under the influence of manga and anime. All these teenage girls who don't give a crap about gay rights will realize, once they get to college, that yaoi isn't some abstract idea. It's a form of human attraction. What will that do to gay rights?
I think that otaku will adapt the Japanese cultural practices and morals into their own life. I myself took on a lot of determination and impression of how I could change my own life, as well as other positive messages, from anime that I watched from 2001 to the present. We won't see direct influences, but if a sociologist were to start studying otaku now and tracking samples, there'd be a very, very interesting book or paper there.