Wouldn't be bad. Of course, out of game you can do that very thing in your server forum, too. 
I like the premise of the suggestion and to throw out a slight variation to it, I've always felt that sg bases could be so much more than just dump depots or a place to use teleporters.
I know SGs have the MOTD function but how about something that spans coalitions. A 'chalkboard function' where you can put on notice items of interest.
Want to set up a tf at a specific date and time and let everybody know? Put it on the chalkboard. Want to let people know about items for trade/sale, list them on the chalkboard. You get the idea.
We know that the sg MOTD has only a certain amount of text space but a chalkboard function could expand or serve a greater role in sg/coalition communication.
I know many people have missed out on a tf/sf before because they weren't online at the time to get the headsup for it. People who weren't online could simply head to the sg base and 'click' on the chalkboard to see the latest news.
Yes, you could arrange events on the specific server of interest here in the forums, but its a given that not everybody is a forumite.
The Mentor Project - Because we were all new to the game at one time...
http://boards.cityofheroes.com/showthread.php?t=212083
So i was thinking, instead of people having to send countless tells over and over to people to ask if they want to join a taskforce, why not make a spot in a few zones where people can click to say they would be interested in doing one, like an in-game sign-up sheet; and when there was enough for a full team or so, everyone that was interested would get a message from the game saying that there were enough players online to do it, and what their names were. This could allow for players to stop wasting so much time sitting around trying to form TF teams, while still being able to play the rest of the game and find a team at the same time.
And if the player logged off, that person would be removed from the sign-up sheet and would have to re-signup. Also, having a handy list of what the level limits of each TF was, a brief description, and standard time necessary to beat each TF would be nice to have with the sign-up center as well.