This puts it up against the most powerful Android phone available today, the Samsung Galaxy S. We can likely assume the phones share 512MB of memory, Bluetooth 3.0 and a screen resolution of 480 x 800, though between Samsung's 4in Super AMOLED screen and Dell's OLED 4.1in display we'll have to see which one provides a better viewing experience.
Based on our familiarity with the excellent Dell Streak, we think it's safe to say that the Thunder will feel more like a premium device, and it certainly looks it! Its camera not only has a higher megapixel count, but also features flash. The device leaked to Engadget was running vanilla Android, but Dell is more than likely to apply its own skin should the device come to market.
On the other hand, if Dell ships the Thunder with the same 2.1 version of Android as it will update the Streak to, Samsung will by that time probably already be on version 2.2 (Froyo). Its 1GHz Hummingbird processor is also faster than the Snapdragon CPU which will likely be stirring at the heart of the Thunder, and the Galaxy S should be superior for 3D gaming, which might be coming to Android soon in a big way. It also has a higher capacity battery, 1,500mAh compared to the Dell's 1,400mAh.
We should find out either way before too long, but in the meantime, which phone do you think will win your heart (and cash)?