1. Key Lime Pie is delicious. I'm not sure who these people are who don't know the taste of key lime pie, but they're missing out.
2. I don't see how this is helpful to nestle and the kitkat brand. If there's a major security compromise or the OS ends up being horrible, this is bad for the kitkat brand. If there is a recall of kitkat bars due to tainted ingredients, this is bad for the android OS brand.
From a marketing perspective, there is just too much downside and not enough to gain from this branding partnership IMO. Android didn't need kitkat and kitkat didn't need android. All they did was get a quick splash of publicity while diluting both of their brands.
They should have just stuck with a generic name. If not enough people know what a key lime pie tastes like, name it chocolate mousse or something.
Edit: That being said, the marketing campaign seems to be really well put together. I just think the partnership is an necessary risk for both brands.