My Beagleboard Xm rev C arrived in the mail the other day. (After I made the required promise not to use it to make nucular rockets or other weapons of mass destruction - seriously).
I haven't got a monitor right now (my last one blew a CCFL and the new one isn't here yet). I tried it first on the telly (HDMI in) but no joy -possibly due to the issue below.
To power the Beagleboard, I plugged it into the PCs USB (out of ports on the Mac), which made the lights come on. With the serial port connected, I got serial noise. Selecting the correct 115,200 baud rate produced startup messages from u-Boot (the bootloader on the supplied demo MicroSD card). It then went into the Angstrom OS and crashed with a "Kernel panic - not syncing : Fatal exception in
A quick google reveals that this is due to the host (my PC) trying USB On The Go (OTG) handshaking - on account of it's newish, and can. This was fixed by the simple expedient of shutting the lid and thus making my HP into a $2000 power supply (I do have a USB supply, but it has a fixed Micro-B plug - the BB is Mini-AB).
That got Angstrom booted to a login in serial, and connecting a network cable resulted in it getting an address and being accessible with SSH. The only downside is that it picks a new Mac address each boot (there is no manufacturer Mac address on the fairly basic Ethernet interface on the Beagleboard). This means that my hub sees it as a new device and allocates a new IP address every time, so one doesn't know where to SSH to.
That's also quite easy to fix as documented here - making an entry in /etc/network/interfaces gave the device a locally assigned IP out of the DHCP space. An entry in /etc/hosts finished it off.