In the 11 years I've been on the internet I've posted a variety of remembrances on this day in a multitude of locations; I've also posted a collection of his Mark's Remarks editorials to my website (it's on Geocities just now; look for a new address soon). This year I'd like to consider Mark's Remarks itself.
In its time, Gruenwald's Captain America was my favorite comic book series; his Marvel handbooks had an obvious impact upon me, I truly enjoyed Quasar and I was deeply moved by DP7 & Squadron Supreme; but the place where I was first struck by the weight of Gruenwald's intelligence was in the Mark's Remarks column of Marvel Age magazine.
Issue #100's Remarks was my favorite; I photocopied it so that I could tape it on my bedroom wall and I could quote most of it by heart (still can). Gruenwald's sense of humour came through in many of the editorials and I enjoyed that, but it was his frankness about the comics industry which I truly appeciated. I had never seen a professional comics writer speak so openly about what goes into the production of a comic; when Gruenwald would write an entry on how to break into comics he was his most controversial because he gave the wanna-bes the straight dope - that they didn't have a good chance and that it would be hard work. Many of Gruenwald's essays explored his love of the Marvel Universe and his thoughts on how to make it function as a proper whole, but he also delved into the process of plotting a script and discussed scripting styles. He spoke with authority, approachability and passion. Gruenwald made me realize that while I might never break into the comics field, if I did I would want to do what he did - write, edit, teach.
Rest in peace Mr. Gruenwald; you are still missed.