Don't listen to the haters. Your tablet's great for taking photos, even moreso when software hacks can boost its resolution from 480p to 720p, as has happened with the Google and Asus Nexus 7.
According to a modder over on the XDA forum, the reason the Nexus 7 can't record video at 720p resolution is because there's no software profile within the code telling the camera what to do, hence the required hack to upgrade its video capture to the full HD 720p spec.
The big problem with the Nexus 7 is that it only has a front-facing camera no matter how clever a hacker you might be, so by unlocking 720p capture you'll have to point it "blind" at your subject when taking your enhanced videos, so it's mainly of use to those who want a better resolution video chat experience. [XDA]