Right now the service is going to be free. It's a lot like the DS Wi-Fi system. So no worries there. As far as games online, we don't really know. The only confirmed ones that I know about are Pokemon Battle Stadium in Japan and I know that in Elebits you can trade user-created stages. Other than that there are only rumors as to which games will have online and what you'll be able to do. If online's important to you wait a month and I'm sure there will be a ton of info.