Implementing Schemas

Lots to learn Mastering XML Schemas is probably a matter of a few days spent initially learning the syntax and perhaps months using it and learning the subtleties. The 40-page primer on the front helps, but the overall document is more like 220 pages.
A six-month (or one year) timeframe? Software developers may face a heavier learning curve - they get to implement all of this and make sure it's correct before shipping it. So far, there hasn't been any work on a conformance suite, and schema implementations are only now catching up.
Potential for subsets It isn't clear how large a footprint code that implements the entire set of rules for schema processing will be. Many developers are already discussing subsets of XML Schemas, though the lines for breaking it up aren't entirely clear.