The fact of the matter is that the majority of people dislike reading from computer screens. The eyestrain is a pain in the butt and you lose a certain something when the text isn't physical. Why do you think eBooks didn't catch on? Most people like to turn a page instead of scrolling the mouse wheel.
I don't think a web magazine is a great idea. Sure it has some great abilities to be cross-referenced, but unless it's REALLY well done, I don't see it being successful. Web based reading material is usually shorter and less informative than print versions because people want their information in bits and pieces. It's MTV syndrome. Also, a good design would be critical, and that often takes more time than I think most people would want to put forth.
Losing magazines is something we all have to deal with, but it's not the end of the world. There are always going to be plenty of other publications that will have the same or similar info. Since GRM and BCM joined, I've found I read less of both. I read GRM for its tech stuff and BCM because I liked learning about LBCs. I tried Classic Motorsport and I'm not too fond of it because it doesn't have the same feel as the old magazine and I think it tends to dumb down its technical articles. GRM is still okay, but lately the cars they've written about have been either uninteresting or too expensive for me to dream about.
My most recent favorite magazine is Retro Cars. It's a brit mag that covers most of the popular LBCs and other euro cars and has some nice tech stuff on modernizing them and tuning. While many of the purists on this site would have no interest in it, for those of us who enjoy tuner cars, it's a great read. It also has some of the history stuff that BCM had, which is an added bonus.
Really though, you shouldn't worry. If there truly is a need, it will be filled. Thats the beauty of capitalism. If someone finds a market for a product, they'll sell it to you.
Oh, and just because many of you have read the same articles over and over in different publications over the years doesn't mean that it isn't news to some of us. The key to the hobby is getting younger people involved to keep these cars going, and if us young guys (I'm 21) don't know the basics of a B-series engine or about a Spitfire's rear end, then everyone is at a loss. And we want a glossy page with full-color pictures so we can read it in the bathroom.