The Mobile World Congress trade show in Barcelona, Spain, is always massive, and in 2014 more than 85,000 visitors from 201 countries attended the event. Despite MWC's enormity, each year there are a handful of key themes that dominate the trade show. This year, low-cost smartphones, virtualization and 5G were among topics that frequently punctuated conversations on the show floor and in meeting rooms. The Fierce editorial team has taken some time to ponder this year's major MWC themes and what they mean for the future. Check them out in our annual scorecard.