Before you grab your phone and search for Opera Mobile in the Android Market, take notice that this version is beta, and you may experience quite a few issues with it, which is why Opera Mobile 10.1 only has 3 stars in Android Market right now. One other big issue I have with it is that it doesn't include hardware acceleration. While they've warned us it might not come until the final version, it's still a bit disappointing.
But if you forget this, you should remember that Opera Mobile (Opera Mini, too) has the best mobile browser UI on the market, hands down. I only wish the Android team would make their browser as beautiful and polished as Opera Mobile, and also as intuitive and easy to use.
Opera Mobile also brings pinch to zoom, which Opera Mini doesn't have. It also comes with an Opera Turbo feature which basically makes Opera Mobile work the same way Opera Mini does — by compressing sites on their servers and then sending you a snapshot of the website, saving you up to 90% data traffic.