Actually, the IntelliJ IDEA plugin repository is accessible from inside the IDE, with the help of the so-called Plugin Manager that will allow you to install/uninstall plugins, get info on new updates, etc. The site you are mentioning is mostly for the plugin developers who can upload new plugins and updates there. For the IDE user everything is much more friendly and intuitive :-) [ April 11, 2006: Message edited by: Ann Oreshnikova ]
The plug-in model of Eclipse is both the best feature of Eclipse as well as its downfall. Who has time to evaluate 10 different plug-ins to support editing xml files? The beauty of IntelliJ is that it comes out of the box with high quality tools for the majority of your Java development tasks. Then of course JetBrains has limited resources so they cannot integrate every development project hence their need to support the plug-in community.
Plug-in development for IntelliJ does not have nearly the support that Eclipse has and few of the free IntelliJ plug-ins that I have tried added much value. In my view, in order to stay competitive with Eclipse, JetBrains will have to commit more resources to foster plug-in development as well as exert some level of quality control over the available plug-ins. If I can get a quality development tool along with a list of recommended plug-ins then I don't have a problem sending them my money. If I have to start sorting through the sea of open source plug-ins then I might as well switch to Eclipse or My Eclipse.