I've often wondered the same thing. Why is it to Google's benefit to only add a few at a time while Yahoo will show them all?
signup to Google's webmaster tools and you will be able to see all of your site's backlinks. http://google.com/webmasters
yep, Goolge doesn't display all the links for a site. When I do link analysis, I use Yahoo Siteexplorer. Though it will still not provide you a complete list of links, since it will only return the first 1,000 which is, according to Yahoo, sorted based on relevancy.
I think Google considered all your backlinks but they don't show it all. It's a random not like yahoo that they show all your backlinks.