In style, out of style?

I've been shopping while on vacation, and usually from the sale bin. This time, I succumbed to fashion and $17/metre fabric, but for dubious reasons. These are fabrics from Mark Lipinski's new Home line, and purchased from the only Canadian store (in Moose Jaw, Sask.) to carry them so far. So you could argue I'm right in style with the quilting times. They're lovely fabrics, and I think I'll have fun with them, but I succumbed because they're new and they're trendy. Usually I don't fall for that -- I only buy something if I either need it, I know I'll use it in the future, or its a great price (and I still have to love it, otherwise I leave if for the next cheapskate ---uhh--thrifty---person like me.)
But what was unsettling about this purchase is the idea of quilt fashion. Now I make quilts because I like working with colour, fabric, and texture, and because they have longetivity. In my professional life, I write for a newspaper, where yesterday's news is old news. Quilts, by contrast, have sticking power. I'm intending for them to be useful for several decades. At one quilt shop I visited on my trip (and it was a great shop with helpful staff), the saleswoman said the quilts on the wall are changed every couple of weeks (!!!) because they go out of style, the fabrics are discontinued, or the kits for the quilts are sold out. That means even this new Lipinski fabric will be out of date before I can make them into a quilt (since I bought it last week, and I haven't washed it or formulated any sort of plan for it yet). I know what the woman meant-- that quilt fabric is like fashion, changing from season to season. But can a beautiful or scrap or wonky quilt really go out of style? I know it can become dated, but really, in two weeks? or two months? or even two years?
There's my philosophical rant. Later, I'll post my thrift shop finds and my sale bin dated fabrics.