Kaladesh is bringing Dwarves back in some capacity, and I'm stoked. I've wondered when this was going to happen for quite some time... for the cultural significance of Dwarves IRL, they don't see a lot of love in Magic.
I looked back at every Dwarf in M:tg, and the shoe-in for a tribe-spike is Dwarven Recruiter. Indeed, it's already started:
Dwarven Reruiter will likely fall to $1.50 after it spikes to $4 in the coming days. See if you can grab these for under $1.00 apiece. Foils are pretty much gone, as far as I can tell.. Expect Foils to stick at $10 apiece in the long-term.
Duergar Hedge-Mage also seems like a good spec, and nto just because it's a Dwarf. Foils will shortly jump from $2 to $6+. This is a beast of a card, surprised it doesn't see more Modern play. In a Ghostway/bounce deck, this is really, really strong. The tribe bump may knock it well out of bulk status.
And finally, If you're the type who likes to pad a collection for trades or selection, it's tough to go wrong sitting on a small stack of Dwarven Miners right about now. Who knows: Dwarves might break into Legacy one day. Don't chase these over $0.20 without more favorable data.