The two things I find particularly interesting about Shannon Wright (artist site, last.fm) are her capacity for vocal yowling (in a good way: she has an extremely powerful voice) and her fusion of classical motifs and rock instrumentation.
In the latter respect, there is something a little Muse-like – though considerably lower on the bombast scale.
As for her voice ... It's enormously distinctive. Distinctively enormous. An incredibly full, forceful alto, with a characteristic waver – almost like a tape warble – to it.
It features a key-shifting, vaguely Chopin-esque arpeggic piano, punchy drumming and aforementioned vocal yowling.
Here's a video of a live show, too – for a taste of her guitary antics. Rock.