A card slot is still a big deal for me for a device that would be used for traveling about. I mostly vacation at places that don't have WiFi. How do I watch movies?
Take my iPod touch 4 for example. It currently has 3GB available out of 6.4GB total. The reason it has so much free space is because it doesn't have enough to begin with to make it worthwhile to load large amounts of content. Because of its very limited storage space, I only use it at home (audiobooks, podcasts, and streaming music). I would never dream of taking it on vacation.