This task is to brainstorm about a live brush preview and where it would be useful. Just with a little bit of discussion, it already appears different people are wanting different things.
Hopefully we can collect a lot of feedback here and make the best decision possible. The main questions is what could use a live preview and why would it be useful.
A small demo of something Scott started with a live preview:
Live preview in brush editor area mockup (deevad)
Older version of Krita that used a scratchpad area for bigger icon.