Yvonne and Liz Kane consider their style to be heavily influenced by South Sligo style fiddling.
The Irish Fiddle, an excellent site all about Irish fiddling includes articles on fiddle styles (one is by Martin Hayes) and an audio clip from an interview with Kevin Burke. I also looked in "The Companion to Irish Traditional Music," edited by Fintan Vallely.
Here are some very broad generalizations, drawn mostly from Eithne Vallely's article on fiddle styles in the "Companion" book.
Vallely describes four regional fiddle styles--Donegal, Sligo, Clare and Sliabh Luachra--with the regions running north to south on the western side of Ireland. Others identify more regional styles, there are individuals who have developed their own personal styles and, of course, musicians from any region may include elements from any style of fiddling in their playing.
Donegal playing features short bowing strokes, with one stroke per note, is very aggressive (Kevin Burke describes it as "brisk") and does not include as much ornamentation with the left hand. The repertoire includes tune types from Scotland. John Doherty was a renowned Donegal player from the mid-twentieth century, while Altan's Mairead Ni Mhaohaigh and Ciaran Tourish currently take Donegal fiddle playing around the world.
Sligo style is also fast and features ornamentation with both the left and right hands. The bowing is smoother, but still rhythmic. Michael Coleman, from south Sligo, was recorded in New York from 1921 through 1945. His recordings influenced many fiddle players at home in Ireland and in the U.S, so Sligo style is what many people think of when they think of Irish fiddle playing.
Clare style is slower, with fluid bowing and much ornamentation by the left hand. Kevin Burke describes it as melodic. Martin Hayes' personal style shows Clare's melodic focus.
Music from the Sliabh Luachra region, on the border between Cork and Kerry, is often associated with dance tunes, and is rhythmic with ornamentation primarily from the left hand. The repertoire includes slides and polkas, but also slow airs.
