Hardcoreware just posted a review on the Intel Core 2 Duo & Core 2 Extreme. Here's a taster:

It wasn't the slaughter-fest we might have expected, considering the hype and rumours, but one thing is for sure: Intel has the better CPU right now. If not for AMD's enormous price-cuts, there would be absolutely no comparison; instead of comparing to an E6400, the 4600+ I bought would be priced in line with an E6700 instead, which would have completely destroyed the 4600+ in every test.

Intel probably could have launched Core 2 Duo at a higher price point, and AMD would not have had to take such desperate measures to keep up with them, cutting prices of their processors in half in some cases. So while it wasn't a case of Intel destroying AMD across the board, we get something more important: competition in performance AND price. It is possible that Intel launched Core 2 Duo with such an aggressive price point to hurt AMD in ways more than just performance; AMD shares already hit their lowest point in a year, before being downgraded by most stock market experts after announcing their bid to buy ATI. Slashing prices of their products by half can't help matters much. Unless AMD is working on something significant, they might just run into the "Gigahurtz Wall" Intel did with NetBurst, and get left behind.

Of course, not every aspect of computing was a win for Core 2 Duo. Thanks to the price cuts, AMD was able to keep up in some regards. Here's how things looked:

• 3D Modeling: A tie in Maxon Cinema 4D, with a slight advantage going to Intel in shading performance.
• System Performance (zipping, encryption, antivirus, etc): Large advantage to Intel
• Video Encoding (DivX, XviD, etc): Huge advantage to Intel in DivX. Less significant in XviD.
• Audio Encoding (MP3, OGG, WMA): Slight advantage to AMD in MP3 encoding. Intel did better in OGG; tied in WMA
• Gaming: We'll call this a tie. Core 2 Duo might do better in future games, if 3DMark 06 is to be believed.
• Internet Content Creation (building websites, flash, video, simple 3D modeling): Huge advantage to Intel
• Office Productivity (spreadsheets, documents, databases, antivirus, etc): Huge advantage to Intel