Oh, and Jonathan, don't worry about getting this tidbit into office.microsoft.com. Who needs it! Your blog came up as the #4 result when I googled <"mark all as read" shortcut>.
A year ago I’d tried entering “mark all as read” into Outlook’s online help, with no luck. What’s instructive is that I tried it again just now, and it’s still not giving me any useful results.
Now, Office online help has a great web-based system that takes into account dynamic user ratings to get better over time. The problem is that this only works if you already have a help topic written on a subject! With no topic to begin with, and no obvious way to suggest one, Office help is never going to come up with a good result for “mark all as read”.
This is where web search engines really come into their own. Sure, maybe “mark all as read” is an esoteric power feature that only 0.1% of Outlook users will ever want to automate. That puts it way out there in the long tail of potential topics about which it’s probably not worth writing official help articles. But someone, somewhere will blog about it, web crawlers will rank those articles, and suddenly people start trusting search engines instead of the official help system.
Also, only #4? Let’s see if this pushes it to the top of the list 🙂