The Samsung Galaxy S smartphone is a very successful Android device and no doubt the next generation Galaxy S, the Samsung Galaxy S II will do just as well, and today we have a couple of preview videos of the Samsung Galaxy S II in action for the Android faithful.

The Samsung Galaxy S II preview videos come our way courtesy of the guys over at Slash Gear and Android Community, and were made by the guys over at Mobile-review who managed to gets some playtime with the Android 2.3 Gingerbread packing handset, albeit a prototype.

Improvements with the Samsung Galaxy S II include a new 4.27-inch Super AMOLED Plus screen, DNle+ image processing technology that is similar to the Sony Ericsson Xperia Arc Bravia engine, although apparently it is unclear if this prototype sports the NVIDIA Tegra 2 dual core processor or the Samsung Exynos.

The first video below is the Samsung Galaxy S II preview footage lasting two and a half minutes and the second video pits the Samsung Galaxy S II against the original Samsung Galaxy S in a UI speed test.

So I’ll let you make the jump and hit those play buttons to check out the Samsung Galaxy S II, and who knows at this rate the Galaxy S II may even see the light of day before the HTC Thunderbolt…enjoy.