Please read this, from Google Webmasters Central:
http://www.google.com/support/webmasters/bin/answer.py?answer=40349&query=cookies&topic=&type=
Make your site easily accessible
"Build your site with a logical link structure. Every page should be reachable from at least one static text link.
Use a text browser, such as Lynx, to examine your site. Most spiders see your site much as Lynx would. If features such as JavaScript, cookies, session IDs, frames, DHTML, or Macromedia Flash keep you from seeing your entire site in a text browser, then spiders may have trouble crawling it. "
- Based on this, my initial thoughts are that Google will only crawl and index the default language version of the page. I would look to append something to the URL to differentiate the two language versions.
I've subscribed to this thread because this is something I'm interested in too, I hope someone else with a little more experience can clarify this for us both, but in the mean time have a read of the above! I hope it helps
- Aaron