I saw some posts and the inquirer article mentioning this, but I'm building a few demo systems for a work project and we're using the MSI K8N SLI board and a pair of Aopen 7800GTX's and it fit.
There is a capacitor in the way and it looks like the plastic portion of the GPU heatsink fan connector is pressing against it, but I was able to get the card fully seated in the 2nd PCI-E slot without any trouble or the capacitor bending.
According to Nvidia they're aware of the issue and are working with MSI on fixing it in a revision of the board. They also said there shouldn't be any issues with the plastic tab touching the top of the cap. I'll post an update if I run into issues!