Meh
16gb is nice, but this size will double every six months or so.
So for now I'm perfectly happy with my 8gb.

I'm in no rush to upgrade.
I'll happily wait a couple of years, by then maybe they (apple and the third party devs) will have a few of my wish-list features implemented & released.
3G, multi megapixel camera, shutter without a 2 second delay, photo rotation-editing/cropping on phone, video & voice recording, safari "open as new page" link features, gps, voice dialing, (fix that damn incoming call interference "Galloping horse" sound), A2dp bluetooth, on phone content management (besides just videos), edge/3g itunes, ipod app with easier sorting (genre by artist or year etc), ipod app with selectable views (album view while viewing by song), bluetooth/wifi syncing, INDUCTION charging, copy/paste, a USEFUL coverflow, ogg vorbis support, SDK (iphone delicious library please?), wifi downloadable apps, longer battery-life, non-recessed headphone-jack, win-syncable notes, flash & java support, calendar syncable with any ical address (google calendar), universal landscape keyboard, "Contacts" not hidden in phone menu (since they're used for email too), maybe even universal cover-flow option (contacts as their pictures?), ability to choose portrait or left/right landscape for videos instead of left-landscape-only, downloadable podcasts ON device, crash/error reporting/log submittal ON device, push email, better speakers, more functionality in YouTube app (commenting system, etc).
Please? ^_^