Brand Names v/s Brand Name Numbers

Brandnama starts this thought off with this link post. He notes that Ikea has memorable names for every one of its products while Nokia only has forgettable numbers as names for its models. I'm not sure Ikea's naming system is working here because all said and named, the name Ikea is the only memorable name in Ikea's stable of names. Besides, sub-products are more likely to fail than succeed or simply be replaced time and again which is likely to dilute the equity of the mother brand. Hmm...no clear cut answers here just an an interesting thought worth pondering. Are we better off naming our sub-products or does it make more sense to go the Peugeot and Nokia number-naming route?