I see.
Multilingual in WordPress is not fun… I once set up a site for a client using a plugin that let me enter the versions of the content and, besides making it hard or impossible to use some plugins with this, it once broke the site because the plugin had not been updated to the latest release of WordPress.
What I ended up doing for that site was what I now recommend to anyone that asks for my opinion regarding multisite in WordPress: have a blog for each language. Back then I did two WordPress installations under the directories /en/ and /es/, but it could ahve been subdomains. Now, with multisite available, you could have a single multisite installation of WordPress and have a child blog for each language.
Yeah, you have to enter the content twice, but you still had to with the plugin. And this way the available plugins are much more, because you don’t add the extra requirement of having it play nice with the multilanguage one.
Just my 2 cents. :)