I doubt 4k a year is a real obstacle to any of Mr. Branson's visions.
If you have a site that is likely to be of interest to a serious player that finds TV attractive, you may suddenly come to a realization of what a unique commodity dot tv is. There are a lot of domain extensions, and aside from dot com and its tremendous first mover advantage, the majority of them are interchangeable on a lot of levels. This is where TV stands out, it is not interchangeable at this time, and even when competing extensions surface it will still have a strong position advantage, as well as being the only sensible 2 letter extension option.
Verisign may be greedy, but their strategy makes sense on a certain level. Their are advantages to holding the reigns on something that is as unique as dot tv.