The dates are finally known - this great event will take place Nov 26th to Dec 24th 2009.
Sad that it won't last until Dec 26th like in 2008 but it seems that after Christmas, it wasn't a commercial success. 

However for this 15th edition of the christmas market of Montreux, there will be an additional site featured. A Christmas village in the mountains in the village of Caux above Montreux. This spot offers spectacular views over the lake and will entertain children with numerous games, plays areas, a live nativity scene and Santa Claus's animals 

Of course the 150 chalets will remain in Montreux and plenty of animations will take place at the Castle of Chillon.

Now it really worse staying 2-3 nights in the city to enjoy everything!