Many people who try to give Apple advice seem to ignore that which has made Apple strong. For instance, when The Apple Blog suggests:
To make big strides in the mobile handset market, Apple should aim for the Pearl and Curve market space, either by introducing a simplified, lower-cost iPhone Nano, or by releasing a brand new iPhone model, but keeping the 3G around at a discounted price.They should do nothing of the sort. RIM introduced the Pearl and the Curve basically because they'd failed to appeal sufficiently to the consumer market, because they had failed to put a great camera and good media support into the blackberries. In essence, they admitted that they were unable or unwilling to put together a single device to meet the needs of both markets.
Apple shouldn't do that, for more than one reason. First of all, model proliferation is where madness lies, particularly for application development. If you have to write an iPhone app and you're going to constantly ask yourself, "What's the resolution? Does this model have a camera?", the experience is significantly more complicated, and that comes out in your application design and choices.
Secondly, Apple is known for its design and its simplicity -- at this point, I don't think Apple needs to admit another model is necessary. At best, something like an iPhone nano, as suggested in the pre-macworld coverage: the same basic device in a smaller package. But, frankly, I think they should focus on building the best damn one model they can for several years to come yet.