Must maintain backwards compatibility with XSLT 1.1
Should be able to match elements and attributes whose value is explicitly null.
Should allow included documents to encapsulate local stylesheets
Could support accessing infoset items for XML declaration
Could provide qualified name aware string functions
Could enable constructing a namespace with computed name
Could simplify resolving prefix conflicts in qname-valued attributes
Could support XHTML output method
Must allow matching on default namespace without explicit prefix
Must add date formatting functions
Must simplify accessing IDs and keys in other documents
Should provide function to absolutize relative URIs
Should include unparsed text from an external resource
Should allow authoring extension functions in XSLT
Should output character entity references instead of numeric character entities
Should construct entity reference by name
Should support Unicode string normalization
Should standardize extension element language bindings
Could improve efficiency of transformations on large documents
Could support reverse IDREF attributes
Could support case-insensitive comparisons
Could support lexigraphic string comparisons
Could allow comparing nodes based on document order
Could improve support for unparsed entities
Could allow processing a node with the "next best matching" template
Could make coercions symmetric by allowing scalar to nodeset conversion
Must support XML schema
Must simplify constructing and copying typed content
Must support sorting nodes based on XML schema type
Could support scientific notation in number formatting
Could provide ability to detect whether "rich" schema information is available
Must simplify grouping