You can probably make a case for both but I think that Lowry should get it. He's a more important part of the offense and the team is so much worse w/o him on the court (except lately since Vasquez has been playing well).
Derozan has been getting the public's attention and all the NBATV/ESPN interviews and stuff which is understandable because he's more flashy which is good for him. But the public's view doesn't sway me because most of them are just highlight watchers and don't pay close attention to this team to realize that Lowry is the real engine.
I'd be happy to see both but I doubt it happens because I don't think the coaches will vote a team that is 22-20 or hovering around .500 to get 2 all-stars so I only see one getting in. I expect it to be Demar because he's more popular, but I think it should be Lowry.