I had some time with the brand new GoPro Hero3 Silver Edition yesterday. I gave it a go against the older Hero2 too see if there is any major differences.
GoPro Hero 3: Silver Edition
GoPro Hero 2:
Auto WB (Not possible to set WB on the Hero 2)
As always, the white balance sometimes goes bananas. That’s why they look a little different.
Hero 3 lens is not as wide as the Hero 2. Still Good enough. The glass and the coating is better a lot better than the Hero2. Most noticeable when in contact with bright lights like in the first clip.
With the built in wifi, better lens, smaller and a better housing. The Silver edition is totally worth the extra money. Seems to do better with noise. Just slightly better image quality than the Hero 2.
If you already got a Hero 2, then i would go for the Hero 3: Black Edition. 4k, 2.7k etc..
for the extra bump in quality. It will hit stores November 20th, 2012.