This is not really an issue, but arguably it qualifies as a meta-issue. I have just created a threepenny-gui tag in SO and added the handful of existing Threepenny questions to it. I used "threepenny-gui" rather than "threepenny" merely because that seems to be what askers are more likely to use. However, I just noticed there is a link in the Haskell Wiki page about Threepenny which leads to the new question interface in SO initialised with the (not yet existent) "threepenny" tag. That being so, you might want to take some of the following measures:
Changing the link in the Haskell Wiki to use the "threepenny-gui" tag.
Propose "threepenny" as a tag synonym for "threepenny-gui" and get enough tag users to approve it (there probably are not enough users right now, however).
Remove my "threepenny-gui" tag from the questions and replace it with the "threepenny" tag (or ask me to do it).
I've changed the wiki page and my personal bookmarks to threepenny-gui. There is no need to change the old threepenny tag, for the simple reason that no one was using it anyway.
This is not really an issue, but arguably it qualifies as a meta-issue. I have just created a threepenny-gui tag in SO and added the handful of existing Threepenny questions to it. I used "threepenny-gui" rather than "threepenny" merely because that seems to be what askers are more likely to use. However, I just noticed there is a link in the Haskell Wiki page about Threepenny which leads to the new question interface in SO initialised with the (not yet existent) "threepenny" tag. That being so, you might want to take some of the following measures: