To Jonny - in BA on the A320 and B744 fleets deicing makes no difference to the T/O performance. Same speeds regardless.
To TP - sublimation is a function of both temperature and pressure and I'm not entirely sure that it's the correct term for what occurs on airframes but I could be wrong. Sublimation occurs when a gas turns directly to a solid, or from a solid to a gas, without entering the liquid phase. My understanding of airframe icing is that it occurs either by contact of water with a sub-zero airframe, or super-cooled water with pretty much any airframe. In either case, the water is in liquid form thus has not sublimed into ice in the chemical sense. In the reverse I don't think the ice sublimes back into gas, it is simply that once icing conditions are left the ice melts due to friction from the airflow and is blown away in liquid form. I would speculate that is why a light, low speed aircraft will land encrusted after an icing encounter but a fast jet will be relatively clean.