Yes. From what we're seeing on quite a few 1-word searches, I do think it is arriving. Related thread: Major Shift in One Word Search Results [webmasterworld.com]
My purpose for even mentioning Universal Search in responding to gehrlekrona's observation on website taxonomies, was that the infrastructure Google needed to develop for it could have widely extended uses. The challenges that Google was facing included:
1. Developing comparable relevance ratings for different channels
2. Program the ability to insert any given channel onto page 1
3. Decide on the query term triggers that insert a given channel into the SERP
My conjecture is that this infrastructure can be applied to any segment of the total index thast Google wants to create, and not just the previously stand-alone search channels.