Since I am using the vanputer as a mobile entertainment center, I am considering adding a MAME-like emulator to it to let the kids play their games on the go.
I started to research the idea of getting multiple OSes onto my 32GB SDHC card and booting a media center in an optimized setup or an emulation tool. I did alot of googling and it seemed like folks were not using the Rasberry Pi to do these particular things in the way that I wanted (RaspBMC + RetroPie). You either hosted a media center, or a game emulator, but rarely both. I assume that this is related to the performance of the Raspberry Pi.
I came across BerryBoot. It works as advertised, but just did not have the images I was interested in. I left a comment for the author, so maybe this would be something that is available in the future. If you want to boot multiple OSes, and they already have the stuff you want, it seems pretty ideal. If not, it's a whole other level of complexity.
Since I am not a Linux guy, it was quite intimidating to think about installing an OS that could do both by myself. SO... I decided to punt.
I purchased a 16GB SDHC card from Amazon and am going to install the RetroPie image there, following this tutorial. I will let you know where I get to. If the kids want to watch movies, we put in SD card 1, if they want to play games, we put in the second SD card.
The next thing I am hoping to figure out is a power solution that lets the Raspberry Pi shutdown gracefully when I turn off the van's ignition. Might be a tough one...