I'll let you know tomorrow. I'm having the "professionals" do the job at my place, simply because it is a huge job and I don't have the time or inclination to do it myself - not to mention the ability to get 2 tonnes of broken tiles to the dump.
I tested an area, and it seems that a rotary hammer drill with a broad chisel would easily break the seal between the tile and the yellowtongue without destroying the floor - although it may depend on what type of adhesive was used.
Regards
Scott