> I'd agree that the software monoculture aspect of it is less attractive - webkit is going to have to be very secure!
WebKit is already the de facto standard mobile browser. Opera switching is affecting only a tiny fraction of the market. WebKit already needed to be super secure to keep safe 80+% of the mobile market. Safari has 60% of the market and Android Browser has 25%. Third place is held by the Java browsers on feature phones.
Opera moving over only makes sense as a business, and barely affects the mobile browser space; they are tiny and wasting a lot of resources just trying to stay compatible with WebKit browsers as is.