I find the majority of those mentioned thus far dull as dishwater. There's a really unappealing cosiness to it all; I find them all very middle of the road. The singer-songwritery ones sound like drippy wimp-rock, Coldplay played on banjos. The more traditional music ones sound square and proficient: well-meaning music students.

But instead of being wholly negative, here's an alternative list of youngish (well, 30something or less) guys & gals I actually rate:
Alasdair Roberts, Nancy Wallace, Mary Hampton, Jason Steel, Michael Rossiter, Ewan McLennan, James Yorkston (his latest, trad-material one, not his boring other stuff), Flake Brown, Boycott Coca Cola Experience, David Broad, Trent Miller, Pepe Belmonte,