It's hard to say. I don't know for certain what obstacles lie ahead. I haven't targetted S60 3rd/5th Edition before. I know the latest Qt version for S60 3rd Edition is 4.6.3. That shouldn't be a problem, but there could be bugs/limitations that I'm not aware of.

There are also some APIs that I'm not familiar with, such as utilising the Back/Menu buttons, how the application menu is populated etc. Maybe it's similar to Maemo5 and can be done entirely in Qt, or maybe it's totally different and I need to use native Symbian C++ APIs (I suspect the latter).

After I write the code, I need to find and install the toolchains for S60 3rd/5th Edition, then work through any build issues. Finally I have to test the application, except I don't have any S60 3rd/5th Edition devices.

I'm OK with all that. What really bugs me is that I have to do it in Windoze.