I have one Acer AspireOne Netbook (atom 1,6) and i do use it as multi-purpose emulation platform... It can run fairly well a wide range of emulators... From a plain Atari 2600 to a N64, and probably could handle GameCube or Dreamcast emulators (wich i haven't tried yet)
However i'm up to buy one of these unexpensive ARM 7" minis, i've found some chinese dealer that ships one unit to you for a total price of 70 euro.
I think its a nice device to take with you on a trip without worrying about it being stolen. And i'm sure quite nice to put Aros on, however i don't know how could i manage a dual boot for Aros and WinCE.