It seems like Panther will install on the Lombard seeing that it both has built-in USB & utilizes the the NewWorld ROM (Rom into RAM).
I imagine that two issues will be;
-No Graphics Acceleration (Same issue with Jaguar)
-No DVD Player support (Due to Lombards Hardware DVD Decoder being unsupported, even now)
So, no better suppport than what is currently supported by Jaguar (should run quicker though), but still it's most likely meet the criterior to install Panther. I'd max out the RAM to 512mb before using OS X at all on the Lombard, that'll ease the performance hit it will take due to the lack of Altivec, Quartz Extreme Enabled GPU, CPU speed...etc.
p'z