I also have to accept another problem -- chain slap. With some of my lowest gears, the chain runs loose because the derailleur does not have the ability to wrap that many teeth.
I'm sorry, but that's just a recipe for unreliability. Surely mountain bike dérailleur can take up that much slack? (I only ride road bikes, so I don't know)
If not, I believe the new SRAM Apex groupset will be able to support it - it has an 11-32 cassette (http://www.sram.com/node/2121/brand/sram-road/src/cat)