Having searched in vain for mentions of Xlink in anything other than XBRL, I can see why it looks dead. Although most XBRL advocates avoid talking about it, XBRL cannot exist without XLink, and it's a growing financial markup language. Essentially XBRL compiles metadata into taxonomies(linkbases) executable through Xlink.
The major current drawback to XBRL dissemination is the lack of open source Xlink software, one thing the XBRL communities keep wishing for but won't fund.
Richard Campbell
Senior Enterprise Architect
Federal Deposit Insurance Corporation
Leader, Federal XBRL Community of Practice
http://usgovxbrl.webexone.com/default.asp
703 516 1135