Okay, here's some info regarding the new emulators:
What are Amithlon, AmigaXL and AmigaOS XL?
"Amithlon" and "AmigaXL" are two different commercial products. Both are Amiga emulators running on x86 hardware, just like WinUAE or Fellow. You can't purchase them seperately, they are only sold as a bundle. That bundle is confusingly titled "AmigaOS XL". Publisher of AmigaOS XL are Haage&Partner (http://haage-partner.com
None of these products are official Amiga Inc. products. The publishers do have official AmigaOS licenses from Amiga Inc. though. It should be noted that these emulators are a "dead end" solution: They won't run AmigaOS4 or AmigaDE.
What is Amithlon?
Amithlon is a heavily modified Linux kernel, used as a HAL (Hardware Abstraction Layer). This kernel initialises the hardware and starts a 68k emulator (this is the only process running on the Linux kernel) which then boots AmigaOS. In fact, Amithlon is more an "68k processor emulator" than an "Amiga emulator" because it doesn't emulate the Amiga Custom Chips.
Amithlon is extremely fast due to the following reasons:
1. a very good JIT emulator written by Bernd Meyer (the author of the WinUAE-JIT patch).
2. the lack of Custom Chip emulation
3. there's no host OS eating up ressources
Another advantage of Amithlon is the fact that the AmigaOS running on it has lowlevel access to all the resources of the computer. You can access CD writers, it could theoretically use AmigaOS' 3D hardware support (Amithlon authors don't have a license to use it) and it allowes proper use of a TCP/IP stack.
But Amithlon is not targeted at gamers. Its lack of Custom Chip emulation does not allow you to run old games.
Amithlon has AmigaOS 3.9 included. Official support site is http://www.amithlon.net
What is AmigaXL?
AmigaXL is a port of WinUAE to QNX. It comes with a full desktop version of QNX. Compared to WinUAE, it's emulation speed is slightly improved, it also benefits from the more resource efficient host OS (QNX). AmigaXL is a full Amiga Emulator, in contrast to Amithlon it comes with full Custom Chip emulation.
AmigaXL has some minor improvements over WinUAE: the AmigaOS running on AmigaXL has Virtual Memory and it is possible to start QNX applications directly from the emulated Workbench.
AmigaXL has AmigaOS 3.9 included.