It depends on how it's done calikarim, there is risk in all business, however E* might not be getting all of Voom's exclusives, this is all rumor and conjecture maybe it turns into one company for DBS with Rainbow Media still keeping control over all it's channels?
At least this is one possibility that immediately screamed into my mind, imagine if Voom could use E*'s "dumbed" down boxes to offer cheap multiroom deals? What if E* people do get Voom's channels? It will probably mean a price increase for HD subscribers, $30 more a month? Meanwhile to be fair to Voom and for Voom to stay competitive, that will only include SOME of the HD Exclusives, while Voom is free to go to Mpeg4, use their new bird, and keep adding more channels and HD channels which will keep Voom at the leader in HD spot.
As has been said though, many people know that HD is not at its "peak" we are all climbing the mountain but can't see the top yet (where at least 70% of all programming is in HD, when HD is taken for granted not a special case) but we are moving forward. Voom making enough money on HD without relying on its slow subs pace maybe a good thing. They may be able to take that money and invest in means that could make thier products more marketable, desirable, and advertising.
In any case i think all this is waiting for the spinoff for one reason only, it will raise the value of Voom's stock, and that's not something they want to happen just yet.