jqueryMsg has part of the infrastructure for parsing wikilinks, but the wlink method returns 'unimplemented'.
It should be relatively easy to add rudimentary support. The pipe trick, etc. could be omitted initially.
I am filing a separate bug to move this to the server.
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=43531