I have the same power supply in my current system, and I am also considering an upgrade, and had the same question about whether or not I needed to upgrade my power supply.
My original plan was to go with either a socket 754 or 939 MSI NEO board, as it receives a lot of praise in the Anandtech guides and reviews. However, after exploring the Anandtech forums and other forums, it appears that the MSI boards are somewhat problematic in that they do not play nice with ANTEC power supplies. If you go over to the MSI website, they do not have any ANTEC power supplies listed as being tested and compatible with their boards. If you dig around on the forums, you will find that some people with ANTEC power supplies have had trouble with MSI boards.
From the info I have gathered, ASUS boards come highly recommended and speaking from experience, I have been very pleased with ABIT as a company.