It's merely a novelty. As for usability, Amiga just doesn't hold up.
I use mine to play games that don't work right on WinUAE, or I can't turn into ADFs. Windows software can do almost anything better than Amiga if you know what to get (which includes shell replacements and scripting languages). I still say Linux is only good for web servers and has very poor interface design. Now that Apple is going x86, I no longer have interest in picking up a Mac mini, which means I'll have to wait for their next budget machine just to try out their OS.
I think people are just so desperate to stay away from Microsoft's fluffy code and Apple's condescending attitude. There really isn't any serious OS competition outside the server/embedded market.
A better question is, "What is the purpose of Amiga Inc., currently???"
They have hardly and involvement or interest in OS4 or "classic" Amigas, they have outsourced their platform to a standard PC architecture with a PPC CPU, and their flagship product for PDAs and cell phones is incredibly late, underdeveloped, and unimpressive.
