All one needs to do is to note the tag counts, on the top right of this question, in order to get a subset population (at stackoverflow.com) of where the popularity is.
As of my comment, the tag counts were:
- iphone × 4829
- windowsmobile × 606
- android × 523
- j2me × 301
- symbian × 106
The are other factors, obviously. Do you enjoy writing for Windows Mobile over iPhone or J2ME? Do you know J2ME but want to get into iPhone development? I dont think there is any one correct answer, but the tag-counts do say something about popularity.
