Apparently Derrickson wants to rip-off The Dark Knight in the sequel. Inception/Batman Begins wasn't enough for him...
In terms of what direction his sequel might take if he gets to make it, an emphasis on villains was certainly implied. Derrickson cited Christopher Nolan's Dark Knight trilogy as an example, saying:
"What made The Dark Knight so great was that the origin story of Batman had been well-told, and then it was time to bring in a villain where you really got to go deep. And not just the Joker, also Two-Face. It was a more visceral experience, I'd love to be able to do that for Doctor Strange."
Disposable, rather daft but on the whole charming and a good time at the cinema. The cast is excellent, particularly Swinton and Cumberbatch who share one of the more... wonderful scenes in Marvel's canon, but the real draw is a blockbuster action/adventure film where the set pieces feel fresh and thoroughly engaging throughout. The Inception comparison is thin - this has less gravity (ha) to it because it's a bombardment but what I think Derrickson does very well is something that Cuaron did in POA - he makes it all business as usual, he takes the first act and uses it to gradually introduce the concepts and then bang, we're in, and this is what happens, and at the snap of the fingers there's something else going on. It's quite nifty. It's really got a Potter vibe going on in parts. Also the cape is a great spiritual successor to Aladdin's carpet, have to say.
Pretty amazing this is going to be Marvel's highest rated movie per the Tomatometer. I certainly didn't expect that to be the case. And while the average score is hovering around 7.3, that isn't far off from some of Marvel's best, including Winter Soldier, Civil War and Iron Man.