Symbian seems to be plagued by some of the same troubles as BlackBerry, and has yet to have any success here in the U.S.
Palm WebOS needs to be mentioned in passing, if only to point out that the HP acquisition has at least bought the platform some time.
Another wildcard developers must consider is the carrier. A smartphones success depends nearly as much on the carrier as the smartphone platform. For instance, even as iPhone prices drop, the fact that it is tethered to one of the most expensive carriers keeps it out of reach for many consumers (not that this is necessarily a bad thing).
Finally, standards need to be factored in. According to Dominique Hazael-Massieux, a staff member at W3C (World Wide Web Consortium) and a founding of the W3Cs Mobile Web Initiative (MWI), Web technologies such as HTML 5 are a pretty good starting point for mobile developers.
The mobile Web is usable on pretty much all mobile devices nowadays. . . and you dont need anybodys approval or review to create, deploy and update a mobile Web application, he said. The review process required by a number of platforms makes it hard or impossible to adapt for applications that require privacy- or security-sensitive data.
Since most businesses already have some kind of in-house authorization mechanism, it isnt difficult to apply those mechanisms to Web-based mobile applications. Moreover, the cost of developing a mobile Web site is usually much less than developing a native app, let alone a native app for each of an organizations supported smartphones.
There are drawbacks to this approach, of course. For instance, Web-based mobile apps dont necessarily have access to as many features as native applications.
Even as standards improve, though, dont expect all of these platforms to play well together. They never do. Handsets, mobile Web browsers and smartphone development platforms will continue to be fragmented, and even if standardization solves 80-90 percent of cross-platform development issues (which is extremely optimistic) that remaining 10-20 percent could trip up your development plans or force you to bring in yet another set of developers to tackle mobile middleware.