I've been running 2x9 on my XC Salsa for a few years now. 28/40 with an 11/32 on the rear, I find it depends on the bike/terrain you ride to work out the ratio that works for you. I just used to get sick of constantly changing from big ring to middle then back again, so an inbetweenie big/mid ring worked for me and I have the 28 to fall back on if I tackle a decent hill.
I use an XTR crankset with TA Specialite rings, XTR shifters/rear mech and a SRAM XX double front mech.