Unicode language character

I remember having read somewhere that there is a proposed Unicode
character for specifying the language of a block of text. Does anybody
know anything about this? (I may be misinformed ...)

If it *is* true, then I think it's interesting from an accessibility
perspective. We'll finally be able to change language in the middle
of attributes (e.g. in the 'alt' attribute). Any thoughts on this?

-- 
Karl Ove Hufthammer