Ethereum is going to keep declining until it slowly dies away. I don't think that it is possible to revive it any time soon, to a price level that is above the all time high of around 0.025 BTC per Ethereum. However, there still might be some small pumps along the way, but the general trend should be down.

Ethereum's technology is going to be replaced in the future, just like Litecoin. This just proves that the best technology doesn't matter, the reputation and the long track record of a cryptocurrency is what does matter.