You get cached pages in Bing, the same way you do in Google.
If it has a cache, the little drop-down arrow will appear. Click the arrow, then, click 'Cached page'.
If there is no cache, the arrow will not appear.
EDIT: Oh! Ok. To find info on a specific website, you begin by typing: site:
If I wanted to look at a cache of this question, I would type:
site:answers.yahoo.com How to get cached versions of pages on Bing?
:-)
EDIT: Don't actually click on the question, when it comes up on the Bing search page. Just look directly underneath it; there is a little tiny arrow, if there is a cache available.