Your analysis is fairly thorough. But the third type of value conflict is sneaky, because you quite literally cannot judge the actual demand for a hybrid unit accurately. When the potential market is enormous (as is the case with cell phones and handhelds; the former with hundreds of millions of customers, the latter with at least a hundred million), the analysis of how much of both markets would value the combination of the two markets is hell incarnate.
You cannot do a cross-section of a group that large and have any accuracy. You cannot assume that the two would be valued as merged by most of your customers since the way that people consider and act around those products varies immensely from person to person. It's just too big a userbase to risk that kind of venture blindly.
About the only effective way to pull off a tactic like that for a cell phone/handheld gaming system hybrid is to test-market the product in a select few large cities throughout a nation. If the product does not take off, then odds are good that the product will not take off in that nation.
Sky Render - Sanity is for the weak.
