There is still no official Ruble sign... but a grass-roots campaign begun in 2007 seems to be be making some headway. A number of font companies are shipping fonts with a ruble sign in them which seems to be being used in the wild.
http://www.artlebedev.com/mandership/159/ I've written Lebedev to ask if he's heard anything from the Central Bank. Michael Everson * http://www.evertype.com/
