Andronicus, the reason why XBox Live Indie Games aren't allowed in Australia is because the Australian government has idiotic censorship rules about videogames. XBLIGs are unrated and so the Australian government doesn't allow them (note: they're unrated because getting official ratings are expensive, not because they're inappropriate in most cases). If our games were on XBLA instead of XBLIG, then we might be able to release in Australia, but XBLA costs more money than we can afford at the moment. So don't blame us or Microsoft, blame your own government.
We started out with XBLIG development because the barrier to entry is the lowest. Since I already owned a PC & a 360, becoming an XBLIG developer only cost $99/year to register (all the development software is free). Becoming an iOS developer would have requited purchasing a Mac & an iPhone/iTouch/iPad and becoming a PSN developer would have been even worse and required getting official approval from Sony and purchasing an expensive development kit. Plus, XBLIG is easier than most platforms to develop for since it uses C# which is good for us since I'm a hedge programmer (self-taught).
Will we support the PSN in the future? Probably not. The PSP is on death's door and the PS3's sales have been seriously lagging behind the competition of late. More importantly, the system was just recently seriously cracked so piracy is likely to become rampant - not exactly a great environment to start developing for. I'm a big fan of Sony as a gamer (loved the PS2 back in the day and the PSP is my second favorite system after the 360), but it doesn't make a lot of business sense at the moment to support them.
As for iOS support in the future, that's a bit more likely, though we still haven't decided anything for sure there. We've received lots of requests to put our stuff out on various phones so there's probably a market for us there. The big problem is porting - whereas porting to the PC or WP7 would be relatively easy since our games use XNA & C#, porting to iOS would require a complete engine rewrite since they use different programming languages. The ideal circumstance would be if an experienced iOS developer or publisher came to us and wanted to license our games for the iOS.