Bitcoin dominance had been slowly decreasing, but has jumped up again with all the market uncertainty. I am hoping that it will fall back below 35-40% over the next few months, it is not healthy for a market to rely so heavily on one coin, especially when, as you rightly said, the next 5 coins swallow up another 30% of the trading volume. It will take time before there is true diversity and the coins move (relatively) independently, but as the overall value moves higher, it should break down more.