Given I've written pretty extensively what I expected from the scrum board, I will just post a link : http://devnet.jetbrains.net/message/5285124#5285124
I'm very disappointed by the current scrum board because this is not easy to use at all for me in my day to day work especially for planning !
For me, the current scrum board is more a kanban board than a scrum board.
If you have only 3-4 active features / sprint then it may fit but given we implement around 10 features / sprint and that we do not split features in task...
I'll continue to use PivotalTracker as a planning tool because it is way more easier to use for that task (especially long term planning) and I'll continue to use YouTrack to track features and bugs content)