Now Sony communications director Patrick Seybold has acknowledged the problems in a blog post, and says that Sony is working on solutions:

We are aware that some people may be experiencing difficulty in accessing the PlayStation Home beta at present. This is due to overwhelming demand for the service as people access Home for the very first time since it became Open Beta and appeared on the XMB.

While we prepare solutions to ease the problem, you may continue to experience difficulties accessing Home. We kindly ask for your patience as we work to meet the incredible demand for this revolutionary service.