I agree with an earlier post, La Liga in HD is worth 15.00 a month by itself - for me at least. WorldSport was the single most important factor for me to give Voom a try.
That said, I find that I do like some of the other Voom exclusive offerings. I think Rave, with continued content additions, will be a solid channel that I will continue to watch. Ultra, Auction, Gallery, and Moov all have some interest for me and, even more importantly, for my wife. They are taking the edge off of losing some of the channels she liked on DirectTV. If more new compelling content gets added to these channels, they too will be solid HD channels for certain niche audiences.
Most of these forums are dominated by men and the talk about channels, programming, and content tend to focus on what men like - Sports, action movies and series. Other type of programing gets devalued. As HD gains more market penetration there will be other audiences - women and men that aren't the alpha technology adopters - who will be eager to watch a completely different set of programming. There is a reason that TLC, Bravo, HGTV, BBC America, and Food have found significant audiences in the last couple of years. That audience has probably been/continues to be the slowest to adapt to HD but eventually they will have HD sets and will want to watch the type of "cultural/style" programing that Voom is offering with some of it's exclusive channels.
So, I guess my point is that I think these channels, while not necessarily my first choice of entertainment, are actually composed of some nice shows (albeit too few nice shows at the moment) and they are a value proposition in certain families or with viewers that aren't strictly sport obsessed.