DDR3 vs. DDR2 - Performance tests on Intel P35 Chipset
 

What this review does address is the performance of the new DDR3 memory that is launched with P35. The new Intel P35 chipset, known as Bearlake during development, supports either DDR2 or DDR3 memory. This presented a perfect opportunity to look at the performance of both DDR3 and DDR2 on the new P35 chipset. We were also able to compare performance to a Gold Editors' Choice Intel P965 motherboard. The results of these comparisons provided interesting results about the capabilities of the new P35 memory controller. It also answered the question of whether you should care about DDR3 in any upcoming system purchase.

http://www.anandtech.com/memory/showdoc.aspx?i=2989

while needed article it's quite pointless don't you think?

they answer that question on the first page:

Their commentary may need some work, yes, but they've gone and provided some very good data. The new chipset seems to offer great memory performance, and DDR3 even at extremely high timings has a surprisingly small negative impact on performance, if not actually gaining a couple percentage points. I was expecting DDR3 to be performing much worse than this.

Another way to put it is that DDR3 IS slower, but P35 chipset helps to reduce this "Deficiency". Bottom line for new system, buy P35 and use DDR2, right?

looking at the price of DDR3, you'd be mad to buy it:)