Sun has confirmed that it is to use the GPL Open Source license to open source Java SE. Although this is considered the most restrictive of the open source licenses (mainly because it forces derivitive works to also use the same license), this does allow Java to be more Linux friendly (which itself is mainly licensed under the GPL). Sun is using a clause in the license however that allows any applications developed using Java (since these are not derivitives of the Java product itself) to be licensed how the developer choses.
More details in this article on news.com.