How many URLs in Sitemap

Well, if you have a site more than 1000 pages, you would have wondered this. How many URLs can I stuff inside one sitemap? The sitemap has become considerablily big. Will Google index all the pages I have mentioned inside?
Well this is what Google has to say.

1. You can have a maximum of 50,000 URLs in one sitemap. Isn’t that cool?
2. The sitemap file should not be over 10MB in size when uncompressed. Hmm. Sounds fair.
3. If you have more than 50,000 URLs create multiple sitemaps and list them in a Sitemap Index File
4. Your sitemap index file should not cross 1,000 sitemaps

I guess these 4 guidelines by Google would resolve all your queries. I am not sure about Yahoo or MSN. If any of SEO Mind readers have an answer, please do post them here.