According to someone who is more closely involved with wiki creation than me, having a web interface for stewards would be pretty scary. Wiki creation breaks often enough that you want to have someone competent on hand, with shell access, to deal with any problems.

As I said in my private email, renames are much more complicated. The task I wrote today would help with renames, in that it provides a way to notify services when wikis are renamed, but there are a lot of other known issues with renames to fix.