I've noticed the changes and improvements since I downloaded this new version.
For starters, the logo is a darker shade of color. Instead of the light-orange and light-blue deal we're used to, it's now a darker version. Here's a look of the logo on my desktop now:

If you ask me, I like it.

It's definitely faster, no question asked. I tried it on my Vista Laptop and boy was it fast! I think Mozilla has created the fastest browser, period.
It's got a "New Tab Button". You just click it and you get a new tab. Will take some time to get used to.

:
Other than a slight upgrade to the graphics of your browser, (So slight it almost is unnoticeable.) there's not much else.
Still, it's a nice upgrade and I'll be keeping it for the time being.