Patch to trunk process

[David Stuart]

I was wondering what the process is for getting patches approved for  
adding to trunk is it a vote based thing? Is there a big review of  
patches when a pending release is close? The reason for asking is i  
have a patch submitted and am in the process of writing a plugin and  
it makes it difficult when I have to maintain multiple instances to  
patch against and dealing with need some of the functionality of the  
first patch in the plugin then creating patches from there etc

Regards
David