They can be added now in your themes…   we explained how to do it in our 4.x wiki, but that needs to be updated for 5.0…  so can add that to our list…

we do want to do a pluigin for this, but need to provide the initial support for 5.0 first…

codex entry is done…  instructions on how to add:

http://codex.simple-press.com/codex/faq/problem-with-post-edit-buttonow-to/problem-with-post-edit-buttonow-to-add-twitter-facebook-plus-one-or-other-buttons/