Amyzing puts it down. Many of us have long argued on XML-DEV that XML has only one real data type: string. Higher-level views and models can add whatever types they like, preferably in a pluggable fashion, but core XML specs should stay out of such quagmires. Amyzing has a go, in her own inimitable way, at getting this message across. The divagation trails off at the end, unfortunately, so I look forward to future installments.
BTW, my latest jab against XQuery and what it stands for is published: Is XQuery an omni-tool?.