We continue to work towards the S4B convergence.
Official roadmap for the convergence: https://skypeandteams.blob.core.windows.net/artefacts/Skype%20for%20Business%20to%20Teams%20Capabilities%20Roadmap.pdf
-WarrenConnor Slack commented
I prefer having them separate. I find the Teams UI and functionality to be much better & easier to use than the interface for skype & our users feel similarly. We've actively avoided using skype for team chat thus far because it's so messy.
How I break this down is:
If you want a more video-conferencing centric chat application, use skype
If you want an O365 integrated and managed alternative to Slack or Hipchat, use Teams.
Please do not merge the two.