Marware has introduced a number of new cases for the Apple iPad. The Eco-Envi for iPad is an envelope sleeve-style case made from RoHS-compliant leather, featuring contrast stitching, a secure Velcro closure flap, and an environmentally-friendly fleece interior. It sells for $50. The MicroShell for iPad is a thin polycarbonate case with a flexible design to minimize stress when inserting and removing the iPad, open access to ports and controls, and…