I frequent these forums, and watch for bitcoin-related news on the Web. I've never heard of Paysius until I stumbled upon this thread. It seems to be well designed and built. I just checked on the Bitcoin Wiki, there is nothing under "merchant solutions" (which looks scary, by the way), nor "shopping cart interfaces."
The obvious concern is that great, functioning, and simple things like this one do not get exposure they deserve. It'd be a shame if bitcoin fizzled out because of problems of this kind. The network is there, tested and tried. Solutions like Paysius are also there, and there are more coming, but potential new users have a hard time finding out about them.