If you write CAD-related applications for mobile devices like cell phones, then you may want to study the words of Michael Mace. In Mobile applications, RIP, he explains why it is pointless to write software specific to cell phones (handis, mobiles) any more.
The combination of splintering platforms, shrinking distribution channels, and rising costs is making it harder and harder for a mobile application developer to succeed. Rather than getting better, the situation is getting worse.
The solution, he figures, is...
...an alternative platform for mobile developers. It's horribly flawed technically, not at all optimized for mobile usage, and in fact was designed for a completely different form of computing.... If you haven't figured it out yet, I'm talking about the Web.
It's a worthwhile read from someone with experience in the industry.