If it was being sponsored by Nestle baby foods then I'd be shocked. That would be insidious advertising.
However, the sponsor is another brand that happens to also own a baby food brand. Yes, Nestle have violated the international code regarding marketing of formula, but then so have all the other major baby food manufacturers (I know, I've just read the IBFAN report). The original reason for the Nestle boycott (v aggressive marketing of formula in 3rd world countries) is no longer the case.
I don't see the point in a continuing Nestle boycott myself, and I certainly don't condemn netmums for being sponsored by a coffeee company. some of the companies who own brands advertised on mumsnet will be dodgy if you dig hard enough.