I mess up my wordpress blog and never even update it for almost two months. I'd like to erase the blog although it has PR2. I'd like to change it to something like a directory and the second database would be the blog itself. would it also affect the PR of the site? and will it still appear in the google search result?
Definitely it will affect your PR. Some of your dofollow backlinks are pointing to your current blog pages URL. If you change the permalink or remove completely the page, it will definitely affect your PR.
thanks. what best should i do with this kind of site? i don't wanna use wordpress anymore as its updating regularly and i cant bother myself just to update. should i change the whole site of just sell it to some one interested?
If you have no interest in maintaining this blog, you can always sell it too. Next PR update is expected by end of this month. If you betting your PR might go up, it is worth to wait before next PR update before selling at slightly higher price. If you don't care about PR, then you can go ahead and start a directory or any other new type of site using this domain. A few quality backlinks will gain you some PR in a matter of time.