sounds good
personalized tactics trainer
Not that it wouldn't be a good idea but coming up with good tactics from games is kind of hard. It is easy to find positions where a better or even winning move could have been made but those are not always tactical in nature.
Often the position has to be manually modified to make a good tactical puzzle. Not sure how well a more automated system would work in practice.
I think it would be really interesting if we could create problems derived from our own games. What I would love to see is a feature that presents problems based on inaccuracies and blunders identified in analysis of our own games. Perhaps every time we submit a game for analysis, the inaccuracy and blunder positions could be added to a personalized training database to allow us to easily go back over those specific positions again.