Oh PLEASE!!! Don't wish the summer away already!!
It is nearly always the first weekend in February, but that isn't written in Stone. I think the 'Powers that be' generally announce the date much later in the year, but first weekend in February is a pretty good rule of thumb
Flights for February will be cheap for a long time to come yet. Also... I have noticed that Ryanair have subtly changed their pricing structure. They now charge a medium rate for long term booking... get into 3 to 12 weeks away and wait for the special offers that will bring the rate to its lowest and book. The price then steadily goes back up to its highest for last minute bookings.
Easter is early'ish in 2012....7/8th April.... which can result in an early Cos Blanc. I would not be surprised at a 29/30th January Cos Blanc but 4/5th February is favorite.
I would not book yet.. leave it until you know the dates from looking at the two Salou forums and book your flights when a special deal is active