My copy of Uncharted: Golden Abyss and my 8 gig memory card got here today, and I was shocked at how small the game cases are.
As you can see, the Vita game cases aren't much larger than 3DS game cases. I was disappointingly devoid of a manual, but I guess it's better to start getting used to the extinction of paper manuals at this point. The blue plastic resembles a blu-ray case, only more opaque. The game carts themselves are about 1/3 as thick and 2/3 as tall and wide as 3DS cartridges.
One thing's for sure: having Uncharted is making it extremely hard to wait for the system to arrive. Tune in on Wednesday the 15th to see my first impressions of the system itself!