I\'d like to use regular expressions in selecting elements using the match function. I\'d prefer not to use an external library (such as saxon) to do this.
There are some things in XSLT 2.0 that aren't supported in the built in libraries (there was discussion on the mono mailing list about this but I can't find the information anymore). But most people never run into the corner cases that aren't supported.
Another option is to check out the open source http://saxon.sourceforge.net/ which has great support for 2.0.
EDIT (AB): the above accepted answer may be confusing. There's no support at all and there are no plans in that direction for any of the XPath 2.0 or XSLT 2.0 functions in .NET.