I think that's very likely. Considering how hard-lined Apple has been about other browsers on the iPhone, I can't see them allowing competition to one of the core features (and potentially new revenue stream) of their new device.
Apple isn't really consistent with this. On one hand, for example, the iTunes store runs break even to sell iPods, which apple makes more profit on. To that end, apple would welcome someone else to sell books on the iPad to encourage iPad purchases.. On the other hand, there's the mysterious app rejection policies, which are just entirely inconsistent and unclear.