Only for now, and only if you're one of the people that hasn't cut cable TV service from their budgets. The average American watches 153 hours of TV every month. Netflix HD streams eat up approximately 2GB every hour (source: Netflix themselves and verified by watching my own router traffic while watching HD Netflix streams).

Some simple arithmetic leads us to 153 hours * 2GB/hr = 306GB per month for an average American who gets their TV fix from Netflix streaming or another comparable service. And this is assuming that there's either only one person in the household, or at least that every person in the household is watching the same thing all of the time. Have a roommate who has completely different taste in television? Boom, 612GB/month. Household or family of four? Of six? Happen to lie on the upper half of the Bell curve? You're screwed. Nevermind the traffic used by, you know, actual internet usage.

I'm sure there will be some replies saying "People should go outside or read a book", but the fact remains that they don't. Still think 150GB or even 250GB a month is all that generous?

Probably similar to this: http://en.wikipedia.org/wiki/Keyboard_Mania

You're right, the frustration level is pretty high. It's very difficult, and while I'm glad I own it, I doubt the more casual rhythm game players would be interested. Even Guitar Hero took the idea of Guitar Freaks and simplified it, making it considerably easier and more fun to play, IMO. I could see them maybe coming out with Keyboard Hero as one of the last of the line of games, but there are plenty of other instruments that would be more fun to play first.