It seems that you are better served if you design your mobile site in the style of an App, and your website the traditional 960px grid. Tablets handle the desktop site okay for the most part.
I'm not at all a fan of sites that look like mobile apps. I want the web on my phone, period. Responsive design gives me the full website with the same information architecture, with the bonus of a more mobile-friendly layout.
I'm using it for all my web design work (well, as much as clients will allow me), and I hope everyone else will, too!
It's not perfect, but I wanted to make sure that potential employers could at least read my site anywhere, even on mobile browsers. And I think that's more important. For content-based sites, more designers are moving past pixel-perfect designs, and more on flexible designs that don't necessarily look identical everywhere. They look GOOD in any environment, including odd browser sizes. It's more pragmatic.
If your website is actually an internet app, then I would prefer a native app for mobile OR the app designed for the mobile browsers, like you said.
Maybe you're a busy designer and don't have time (or desire) to always experiment with new techniques. If all of a sudden your industry peers getting excited about something, it's like a signal that says it's okay for you to try this out. I'm not sure if it's a "make efficient use of my time" heuristic about what you should devote your attention to, or a "nobody ever got fired for buying IBM" safe bet thing. Probably a little of both.
But the problem with fads is that they go out of style, so if in two years this whole phenomenon blows over, we are stuck with a large responsive website that we sunk all that time and money into and it just looks dated.
This isn't a Web 2.0-like design style that comes and goes. I'm sure the techniques will evolve in time but I can't see us ever going back to fixed width layouts.
I'm researching Responsive Web Design as an option for a large e-commerce site. But for me, for a large site with a lot of dynamic content and functionality, it doesn't seem ideal to simply shrink it down to one column.
And I also wonder about the amount of time it takes to create designs taking all screen sizes into consideration.
Anyways, thanks again.
Also, responsive design doesn't have to be about getting your website to work on your 2001 Nokia brick's display. A good first step in responsive design is just to take advantage of the full width of the device your user is using up until a point. A lot of websites I view from my netbook could take advantage of just one media query: a full-sized design for large screens and then a fluid width design for anything smaller. I find a lot of websites give me a horizontal scrollbar on the 10' screen.
I think this is true but it is also much more expensive to do. So to answer your question no I dont think it is a fad but is good at bridging the gap between the two.