Dembele is a special talent. People will need to temper their expectations because he is still a 20 year old moving the one of the biggest clubs ever. There will be growing pains and periods of adaptation, and plenty of time where he will incur the wrath of fans.
However the talent is undeniable.
From watching him I can tell he has plus skills in:
Speed
Dribbling
Vision
Cut-and-shoot
Body feints
That's a very impressive offensive skillset for a 20 year old.
Areas in need of work/growth:
Decision making
Shooting
Defensive contribution
Off ball movement
Sound familiar? Pretty Neymar-esque circa 2013. Except I believe Dembele has better body feints and cut-and-shoot skills, while perhaps lesser dribbling skills.
This is a player who will frustrate some early with his decision making and goal scoring conversion rate, but will cause a lot of trouble for opponents having to deal with him in wide areas.