These types of decisions are going to massively limit the number of trademarkable words available for businesses to register in general. It wasn't even like Sky and Skype are directly competing with one another (VoIP/Chat/Video over Ip Vs. Satellite TV). Or that Skype was trying to feed off of Sky's reputation or brand.
This ruling is simply terrible. It is terrible within itself and sets an even worse precedent. The EU needs to pass additional laws clarifying this so that courts cannot reach these kind of conclusions.