I've heard of people adding worm castings to their garden soil, but what happens if you're on the worm casting extreme, and plant directly into worm castings?
While vermicompost does provide many nutrients it will not provide all the nutrients that plants need to grow properly. For instance, vermicompost lacks magnesium; also consider it's pH is roughly >=7 which is neutral, if not akaline, on its own. Most plants enjoy growing in a medium which is slightly more acidic (5.5-6). So while you might find some success planting directly into vermicompost I believe that if you compared the growth of the same species of plant in, say.. a 50/50 mix of vermicompost and peat, then you would see: healthier, faster and more vibrant growth from those plants then you would from the ones that have been planted directly into vermicompost.