You've already read today about the awesome release of the new AM2 platform. With all the hype surrounding the recent release of the AM2 platform, it's good to know what composes the backbone of the various boards we're seeing on the market already, especially from those two companies that are associated with “performance”. ATI and nVidia both have competing chipsets, and there's a good feature breakdown of them already up for grabs. ATI steps in with a passively cooled 90nm CrossFire chipset, the Xpress 3200 coupled with the SB600 south bridge. The SB600, the long awaited successor to the SB450, is ATI's first SATA-II supporting chipset, has native RAID functions that so many nVidia users have taken for granted(though no RAID-5), HD audio and a massive 10 USB ports, and has improved performance over the previous models.
nVidia steps in with the 500 series, including the nForce 590 SLI, that has support for dual 16-lane PCI Ex cards (though that isn't entirely new), a “stock overclocked tested” function they are calling LinkBoost, designed specifically for nVidia cards that are rated to handle it. They've also fixed bugs in the onboard ethernet controller, an integrated QoS feature designed to improve performance of certain applications, and even an integrated connection shotgunning that will let you bond the onboard nics together for a theoretically 2GBbp/s of bandwidth available. Overall, both nVidia and ATI's initial offerings for AM2 seem to be more feature-rich than entirely performance oriented, which makes a lot of sense considering much faster CPUs won't be available for yet some time. Both chipsets are definitely worth looking at.