That's probably a bit pessimistic. However, I agree that there is significant downside risk to AAPL -- maybe to $350 -- if Apple sticks with the 4.0" screen for the next year and unveils/enters no new product categories in that time. The U.S. market is now fairly saturated with iPhones, which means Apple depends on upgrades to generate much of its profit. A significant percentage of iPhone 5 users will not upgrade until Apple releases a larger phone.
If Apple were smart, IMO, they would offer an iPhone with an incremental increase in screen size, such as a model with a 4.2-4.3" screen in a IP5-like form factor. That would entice many to upgrade, and then Apple could unveil a larger 4.7-4.8" super-sized model in a year, to get many of those same folks to upgrade again.
Based on current rumors, it sounds like Apple will release a 4.0" iPhone 5S in late September followed by a super-sized 4.7-4.8" iPhone 6 next June/July. From an investor's perspective, this is just a stupid move because it skips an upgrade cycle that could have net tens of billions for Apple and its shareholders.