You know it's funny; of course, you cannot compete with modern OSes in most cases with the Amiga. That being said, if you can provide Firefox you've met 40-50% of the US users internet requirements. Add the ability to watch any type of movie and play MP3s easily and intuitively and you've captured another 20%. Finally add flash support (I know I know) and you're competing with modern OSes for 90% of non-game playing people on the market.
Many people, sadly enough, are very happy if their computer provides music capability, and modern internet connectivity. You want OS 4.x to be popular and well reviewed, provide the 3 tools above and you've got a big audience.
You'll need to have a decent word processor at some point but music and internet is key. After that you can win more support by simply adding basic apps. Backward compatible Amiga support is needed (either in emulation or native support [not likely]) for retro-enthusiasts to go and enjoy it.
