i think the pico lcd is awesome. i will likely use it in a few htpc's and radio boomboxes.
for our cars though, i would love to see a cheap display-button package. basically, 4 or 5 small lcd's in a row side by side make up one larger display like the pico lcd. they could matrix video together through software to show track, artist info, rss feeds, even full motion video.
then, when needed, the screens could show independant controls, and you could push those screens like a physical button to control what you want.
if we could find good cheap lcd's i would think the hardware side of things would be fairly easy, but getting the software right would be the challenge. the possibilities would be endless though. if an easy button editor program could be made, you could theoretically have a whole new user-made skin database of all the different button and screensaver setups.