Totally. I'm one of those people and right smack in the middle of the crosshairs for this. I'm the kind of person that is always willing to overpay in order to have "unlimited" anything, even if it doesn't make direct financial sense. I'm not sure why, but I guess it's because I don't like having limits or having or budget, etc. Part of the reason I happily pay $9.99/month for Spotify when, if I really think about it, I wouldn't really buy 7-9 new songs a month every month on iTunes. But I don't care -- I'd still rather know I could stream 20 entire albums if I want for that same $9.99.
And same goes with Kindle -- I probably (actually, certainly) don't buy a book a month, but knowing I have a catalog of 600k titles at my disposal for $10 will be a no-brainer.
/psyched