Today, on the 1st of April, I am glad to speculate about plans for new features in MP3tag.
Finally, the 128bit version is to take shape. With the almost unlimited memory space, you cannot only tag your whole collection in one go but also that one of your neighbour as well.
The frequently requested feature to detect duplicates and auto-tagging is finally in the pipeline. The good thing is that not only tags automatically, it also deletes automatically music from dubious sources and styles that are generally rated as crap. The rating is adapted accordingly. It is not unlikely that it is planned to expand the options so that you can set a bias which tracks to keep and which to delete (automatically).
A spell-checker would be so nice to rule out the odd mistake - an incorporated online messaging system informs artists like P!NK that there is something wrong with the spelling in their name.
To soothe the painful syntax for regular expression an expansion for irregular expressions plus an interface to a common speech-to-command service like SIRI or Google should ease the maintenance of each collection. The future of data processing in the shape of the DWIM concept ("do what I mean") is almost in reachable distance.
Some new actions are contemplated, e.g. the swapping of the featured artist from TITLE to ARTIST and vice versa can be done with a special action "Swap partners". With a special switch all kinds of parenthesis can be replaced by all other kinds of parenthesis.
Also the "Correct everything" action is in the final review stages, all based on input from this forum.
With all this in mind, I would say "the future is bright, I have got to wear shades".
Happy 1st of April, everybody.