Future versions of XSL will extend the vocabulary, enabling applications to produce the highest quality print rendering in a standard way. This will also allow content publishers to have a single set of stylesheets that will work in multiple media with different applications. And as the rendering capabilities of monitors improve, and the sophistication of browsers increase, the difference between online and print applications will decrease, reducing the need for widely different stylesheets for them. Here are my reactions to a few of them. XSL is too complex.
Complexity is a difficult thing to measure.
While it is true that it's possible to write very complex stylesheets in XSL, it's also true that you can accomplish a lot without delving deeply into the complexity. If I explain that XSL processes a document by finding templates that match each context and applying them, I don't think that fragment is really very complex. To do complex processing in either system requires deeper knowledge than is required to do simple processing, but in both systems a lot can be accomplished with the simple rules. CSS's weakness is that it can't reasonably be extended to handle the more complex cases. One of the factors that I think has contributed to the apparent complexity of XSL is the fact that it has changed significantly, and sometimes dramatically, between Working Drafts.