DOSBox running perfectly on Vibrant!
It's running inside my old Debian chroot I've migrated from my old Mytouch 3G and Cliq.
It uses a VNC server with geometry 800x480, TWM window manager, and DOSBOX with a config file disabling scancodes, scaler=none, and all audio disabled.
Runs quite well. I haven't tried anything particularly demanding yet, but Moraff's Revenge, some old SSI gold box games, and various Ultima games play just fine.
The Swype keyboard is a GODSEND for emulation on this device. the cursor key input mode is PERFECT for MS-DOS games.