These guys would be #11 on my top ten list of ways to get to the BVI. Has the FAA licensed them yet? Do they have any codeshare agreements? They were talking something like three flights a week. What happens if you miss one, you wait several days?
If you're flying in June, this is the time to be looking for a good deal into STT or EIS. InterCaribbean looks to be providing excellent service - saw a lot of their planes landing and taking off at EIS. I'd book separate flights on Southwest and IC long before considering BVI Airways.