Requesting a workspace is not working yet at the time of writing this post, but I expect it can be opened every moment now.
APEX 5.0 carries many new features, one of the biggest is the new Page Designer which should increase developer productivity even more. David Peake recorded some videos, here's the APEX 5.0 Page Designer Overview:
You find more detailed videos for the specific sections of the APEX 5.0 Page Designer on YouTube:
Congrats to the Oracle APEX development team for delivering APEX 5.0! It looks awesome.