that article says it only protects against interference from microwaves, but don't forget about stuff that operates normally in the 2.4 GHz range (same as the airport) that would cause interference. here's a quote from apple, from the airport 3.11 software update page:
"Base station Interference Robustness, which provides improved performance when 2.4GHz devices like cordless phones and wireless video distribution system cause significant interference with the AirPort network."
also i seem to remember reading something about it automatically switching channels when interference gets too high in the current one.. i'm not sure about this, though, and i can't find any info on it at the moment.