ok so nobody answered... thats fine.. anyway I discovered a way to solve the problem as I was tinkering with it on the 3rd day...

You just have to add another blog on the wordpress app if you want to delete the other blog. It seems that the Wordpress App won't let you have an empty Blog list once you have one registered.

Hope this helps other people who might be using the Wordpress App for the N900 in the future.