My guess is it will continue to be around 50% - 60% of BTC Market share, if it hit's 75% or more than I'm suspecting either BTC had a major technical issue discovered, there was some stupid regulation that hit BTC directly or it'll be time to sell off a lot of ETH and wait for the crash and buy it back.

Right now ETH is my primary hold coin too, so while I'd love to see it sky rocket I don't think it'll hit more than those numbers.