First, though it looks nothing like the dress the Ellen Parsons character was wearing last night, I enjoy this Design History grey pleated belted jersey dress (pictured right). Although the dress hits above the model's knees, I think it will hit at or slightly above the knees on most women. At first I thought the material may be too casual for the office, but perhaps the dress can be "dressed up" with a nice dark cardigan. It also comes in black and carmine (a red that I think is too red for the office). The dress is made from 95% viscose and 5% spandex. Originally $120, Bluefly has it on sale for $72. Find it here.
Second, this grey shift dress with puff sleeves from Target (pictured left) is closer to the dress I was searching for -- but not really all that close. I do like the bell sleeves though -- although the criss-cross front may necessitate the addition of a camisole underneath. 100% polyester; $24.99. Available here.
Finally, I don't really like it, but this cotton rib turtleneck sweater dress via Victoria's Secret (pictured right) is the closest I could find that did not incorporate wool or silk. But, I really, really, really don't like it. Way too heavy and chunky -- and the long-sleeves -- not for me. Nevertheless, if you're interested, it's on sale for $68 (originally $88); find it here.
In the end, I rate my search for a vegan-friendly grey knit shift dress a dismal failure. Guess you can't win them all.