Honestly, these are the things that would TOTALLY bring me back to AmigaOS exclusively - and that a Classic Amiga currently can't do:
- full use of the internet including YouTube, and banking sites (would need to work with web-mail security encryption, and bank website encryption). It would also need to render modern websites properly.
- Full audio multitracking - I know Audio Evolution is capable of this....but right now you need a very hard to find classic PPC accelerator to actually use it with any functionality.
- Non-linear video editing - Sony Vegas style.
Once a "new Amiga" comes out that can handle all of these things (and this would also mean some new Amiga software in the first and last cases) then I'd ditch other operating systems. So I guess this isn't a classic Amiga anymore.
Classic Amiga systems still do a great job with MIDI recording, desktop publishing and graphics (even if they are a tad bit slow for the latter two).