+1 for some kind of revision to keywords. As phred said, it would be great to be able to see/reuse previously used ones and have a typical multi value splitter. And please make it semi-colon separated, for consistency, not comma-separated. That would let me actually use it and free up a custom tag slot.
Did the ... button disappear because of last.fm changes? If any of that functionality comes back, I'd rather have a list of suggestions (like genre used to have) than just a heap of tags I don't have much control over. I always wanted to see what was out there, but it was too much to sort through.