From Dublin, Ireland:
Delorentos
Damien Dempsey
The Frames
The Immediate
Jape
Messiah J & The Expert
Fionn Regan

Not Irish but of interest:
Gruff Rhys (two of his Super Furry Animals bandmates have Irish citizenship, tho!)
Bic Runga (she's only really popular in her home country and Ireland!)
Boom Bip (well, he might reinact his collaboration with Gruff!)

and Dublin's own The Mighty Stef, although not listed there, is playing some SXSW event around then, too.

I thought Simple Kid was Irish |I