Ok bad joke really and not really an issue - although quite annoying.
The guys on the SQL Server team are obviously very intelligent and very thorough, but you're taking things too far when the following occurs:
select replace('Thanks', 'þ', 'B')
returns:
Banks
Ok, it is technically correct (for those that don't know, the Thorn character (þ) in old English meant 'Th'. Side note, 'ye Olde Shoppe' would have really been written þe Olde Shoppe, so pronounced 'The Old Shop').
However, it's not useful and caused an annoying bug when a colleague used a þ as a temporary character when manipulating a string.
It can probably be disabled by manipulating codepages, and is a cute easter egg, but damn! It was hard to figure out what was screwing up the stored procedure.