There are so many iPhone cases available at this point that we see each new release as falling into one of a handful of categories: "no one would want this," "a niche of people would want this," "a lot of people would want this," and "even people who already have satisfactory cases would want this." Speck's new CandyShell Card ($40) fits into the niche category, and SeeThru Satin ($30) is so cool that all of iLounge's editors went crazy when we first…