I agree about external storage, an SD card slot would go a long way but it's Google and I believe the Nexus S and the Galaxy Nexus do not have external storage shots (not sure about the Nexus One?).
This is the worst thing about the N7 but I knew before I bought it so no hardship really, don't regret buying it for one minute.
I don't agree about the 3G/LTE though, I have good Broadband at home and when mobile I have a MiFi which I use for my SGS2 and my WiFi only PS Vita, even if I didn't my SGS2 can WiFi hotspot anyway...
So the only thing I would change is an SD card slot but I don't think Google will give us one of those even on the next Nexus tab because they and many others see the cloud as the future.