I think its important to have, I have already learned a ton via Slack and I have marked several posts there are favorites so that I wont lose them .
The Slack experiment, even though I have been very skeptical at first, has been a huge success and it can easily compete with the importance of the mailing list. Merging the two would be a huge win for our community.
Should we have a digest from slack to a mailing list?
We are already losing messages
Stephan