Dzongkha is lacking a modern vocabulary, so new words must constantly be invented. Mr. Tshering Dhendup of Bhutan's National Council has spearheaded a bi-lingual Glossary of Parliamentary Terms which will be distributed to all National Council members in the upcoming session. More information is available in Tshering's blog post.
This reminds me of the revival of the Hebrew language. Hebrew ceased its existence as a day-to-day language in the 2nd century CE. In the 19th century - almost 2,000 years later - a unique revival process started taking place, and today millions of Israelis speak (and dream!) in Hebrew. As part of this highly successful experiment, thousands of new Hebrew words were invented, and modern dictionaries were written. However, words and dictionaries were not enough: there were no reading materials in modern Hebrew. Thus books, short stories, newspapers, poems, plays etc. were written in and translated to Hebrew.
Back to Dzongkha: Dictionaries are essentials, but there seems to be a lack of reading materials, especially for children. Translating children's classics (most of which are royalty-free) to Dzongkha can be a good first step.