RDM can't get more unique buffs due to the limits on simultanious magic effects on a character, but that is being addressed by the devs currently.
When that is done though, I could see RDM getting a host of new unique self-only buffs like Temper to mirror those traits of BLU. We might not get a Dual Wield trait, but we could get a Composure-like ability (lasting 2 hours) that gives it or a buff that increases existing Dual Wield (if subbed from NIN or DNC).
Perhaps I'm optimistic here, but maybe that's what Encomium's purpose will be: turn RDM melee in overdrive through the buffs.