Summary: With the 3870 X2 AMD has managed to design a card that is finally able to compete with the performance of NVIDIA's high end offerings. The card is based on CrossFire technology which makes both of its GPUs work together for more performance. One major drawback of CF is that scaling is very dependant on the application you are looking at. We saw amazing performance in 3DMark03 for example, where the 3870 X2 could gain over 60% compared to the 3870.
Pros: Can compete with NVIDIA high-end cards, Some overclocking headroom left, HDMI+HDCP+Audio
Cons: Performance largely dependant on application, Noisy, High power draw, Fan speed is constantly changing, No PCI-Express 2.0 support