If Jeff Koons is kitsch then it is a form of kitsch that, for me at least, doesn't seem to match the definitions proposed by Kundera (as quoted by Chris) or expanded on by Allison, and those definitions for kitsch sound right to me, as I would think of kitsch.
Koons' sculptures don't trigger any kind of sentimental reaction for me. The balloon dogs are colourful and can at least liven up a drab public square. But I don't find them making me feel anything more than that. I don't feel myself sharing anything with humanity. Perhaps others do? But if they don't do that are they kitsch? Are Louise Bourgeois' huge spiders kitsch? If they inspire anything in me when I see one of them it is a kind of low intensity phobia.