The retention bracket on the right side is the new one.
Since the mounting mechanism is slightly different, you will require a new processor cooler for your AM2 system. However, many existing designs can easily be transformed to suit AM2.
No Changes In Chipset Support
As we already mentioned in our evaluation of ULi's M1697 chipset, there is no need for new chipsets for AM2, and it won't affect the chipset development of 3rd party manufacturers either. Basically, every core logic product that supports the current AMD64 processor family will also support the Socket AM2 generation, because the communication path between the processor and the system is HyperTransport.
For the time being, Nvidia's nForce4 will remain the dominant product in the Athlon 64 retail market, thanks to its broad feature set. ATI currently has its Radeon Xpress 200 family, but it is in the process of keeping up with Nvidia. In the OEM space, VIA still plays an important role, and ULi as well as SiS are still around as well (although ULi is part of Nvidia now).