It started resurging during the Centennial and took off from there, increasing every year. However, in the last few years I've seen a decrease. The decrease was starting even before the crash of 2008 but has accelerated ever since.
Here's what I've noticed. Our state's quilt guild has fewer members and they've had to cut back on office staff hours. There are a lot fewer quilting books in the crafts section of the two bookstores I frequent. (There used to be 3 rows of quilting books; now there's not even 1.) Plus, I notice fewer and fewer new titles making it to the bookstores. I see fewer quilters buying fabrics at my fabric fabric haunts (can always spot a quilter by her fabric selection!). The quilt shops I get to are less crowded than they used to be, and several have gone out of business. I myself am not buying fabric, patterns and books in the quantities I used to. Also, there are fewer innovative ideas coming on the market compared to previous years. (Hate to admit it, but I think I was at one of the very first demo's of a rotary cutter and mat. We all thought it was a truly revolutionary concept, and it was! Still remember the guy demonstrating the pizza cutter and being amazed at how fast he could cut strips.)
There does seem to be growth in the longarm machines for home quilters -- many more options now than there were even just a few years ago.