moving directories

Currently I have my worpress installation running here
http://www.kodadesign.com.au/vault
it is my business domain website (which is extremely unfinished), and I will be purchasing another domain to use for my blog.
My main concern is, moving all the posts etc. I will be using the same database, as the new domain will be sharing the same webspace.
Any simple way of doing this? Do I need to install wordpress again?
If someone could point me in the right direction that would be great. Thanks.