Sensa had a web site with details of their lovely pens. Now they don't and trying to go to it gets you redirtected to the Sanford (a Newell Rubbermaid company) Consumer home page where one has to dig deep to find mention of Sensa products and even then no details of anything except SKUs and ink refills can be found. The Internet Archive shows the site was there on the 13th of August, 2007.
Both The Fountain Pen Hospital where I got my Meridian Crystal Silver (but who don't list Sensa as a brand) and Overstock.com are still selling them. Perhaps the apparently greatly discounted prices are to clear a discontinued product line from a discontinued brand?
So what happened to Sensa? I've found no news of their demise.