Yeah, MorphOS does look like it's running into a dead-end if the only future hardware platforms are a few different models of PPC Macs. It would be nice to see them port it to the X1000, which they are welcome to do according to Trevor Dickinson, much like OS4 was ported to the Pegasos.
Aros will always be there because it's open sourced, and is only going to get stronger as more people take an interest in it. I doubt it will ever take off in any competitive or commercial sense, but it could soon be the platform of choice for people wanting to set up an Amiga PC for both classic applications and games, as well as current applications. It's now possible to execute any 68k application or game from inside Wanderer (Aros' version of Workbench) and it will open in a native Aros window and use Aros menus and pointer as if it was running a native application. Games will work with joystick support and sound, and be run in a window or full screen. This jUAE-integration is more streamlined than WinUAE and developed much further than eUAE or UAE4ALL. Because it's fully transparent UAE emulation rather than 68k system emulation, there's no chance of an old Amiga application bringing the whole system down when it crashes, like it would in OS4 or MOS. It can simply be removed and run again.
Aros is still rough around the edges but it's evolved a lot recently, and it's already usable as a regular desktop OS for things like web browsing, IRC and MSN, Email, text editing, watching movies and listening to music. There's even a MMORPG on there called Eternal Lands, and it's free to play unlike World of Warcraft, so there's no obligation to get stuck in there all day long to get your moneys worth.
Best of all, it's completely free, anyone can download the ISO and boot it up on their PC. It can be installed natively or run in a VM.
I think the future looks exciting for all flavours of Amiga, and I'm really looking forward to the Natami, which is getting closer to completion and has already got a bunch of games being worked on for it.
Here is AmigaOS for x86 - http://www.icarosdesktop.org
! Why not try it on your PC today?