Steve Jobs does not have a blog, but he does have a website called Apple.com. He has posted his thoughts on Flash at the following URL:
I have written Flex/Flash based applications, and one of the things I like about Flash is that you can write applications that look and act the same on any platform. This does not necessary translate well to mobile devices. I think you are better off writting software for the platform for mobile devices. I have written iPhone applications using Objective-C. I know a lot of Actionscript developers are probably weary of learning a new language, but Objective-C is not that big of a transition.
Jobs mentioned that he thought that HTML5 makes Flash obsolete, but HTML5 even though it is an open standard, the MP4 video format is a proprietary. HTML5 is still an unfinished spec. I think it shows great promise, but the browser vendors will interpret the spec different ways. The nice thing about Flas is that it always looks and acts the same on different platforms.