Allow more characters for Scrabble-type entry and results
This is not the same idea as the old one for Bookworm, since that's a much more limited case (specifically, no wildcards). What I want to see is more length in the flat Scrabble entry interface. All the existing word finders seem to cap out at 15-letter results, which makes a kind of sense given the limitations of a physical Scrabble board. However, these finders could be useful for other games and purposes (like building an optimized "deck" for Clockwords: Prelude).
The dictionary for Words with Friends happens to contain words much longer than 15 letters, as can be seen here:
Currently, it the backend finder engine is actually limited to 16 characters. This is irrelevant for Scrabble's 15-letter-max dictionary, but you can sometimes get a 16-letter result from the finder for Words with Friends (such as "disestablishment"). Considering the Words with Friends dictionary appears to be so much larger, the limit could simply be removed (perhaps as an option, or else in a separate mode). This would expose all these additional words that are already available anyway.
In the long term, I wouldn't mind seeing an even larger dictionary added, including such famously sesquipedalian words as antidisestablishmentarianism.