That is my expectation indeed, if Bitcoin ever solves the scaling problem. If that happens, I expect Bitcoin to quickly double (or more), draining the market share of altcoins.
In the end, who wants to have NEM, Golem, Augur or PIVX? Of course they're only used to get rich quickly, created by someone who felt he joined Bitcoin too late and started his own. And getting rich means getting more Bitcoins, that's the goal of all alt-trading.