C++ – Symbian Development

Aside from Open Signed Online, which is pretty hopeless when you want to debug on the device, the only options at the moment are to find someone with a publisher ID to create a developer certificate for you device via Open Signed Offline, or wait for Symbian to come up with another way to get you a developer certificate. They are already planning to make publisher IDs cheaper and easier for individuals to get (currently you need to be a registered company) and wider availability for developer certificates is also on the cards.

It's probably also worth noting here that the Symbian developer experience is in the middle of a massive overhaul. If you want to start developing native apps on Symbian, then learning Symbian C++ now would be a little crazy. Qt is the new application framework for future Symbian devices (and can be installed to current ones). IMO, Qt is an even nicer framework than Cocoa.

Regarding whether the investment will pay off, the jury is still out. It's fair to say that MOST iPhone developers don't make money - the store is too crowded and the number of junk apps is incredibly high. Symbian app stores like Nokia's Ovi are too new to have meaningful stats, but so far it seems average selling prices are a bit higher. In the medium term, the addressable market for Symbian devices through app stores is going to be much higher, as iPhone is ultra-high-end only, but those consumers are also the ones with most cash to burn on junky apps. So if you want to write gimmicky novelty apps then iPhone is probably best. If you've got a genuinely useful service to deliver, I expect you'll make more money on Symbian.