No, Yahoo don't have PageRank. PageRank is a trademark by google : http://www.google.com/corporate/tech.html PR is not the same as rankings. Yahoo has its own algorithm, though I believe that backlinks are still the most important part of it.
i don't think that yahoo have Any pr kinda thing ... Its google trade mark and you can see Your site's pr via google Toolbar ...but yahoo don't have anything like this ...
Yahoo WebRank is basically a rank assigned to a URL by Yahoo on a scale of 0-10. It was introduced a couple of months ago as a Beta feature of the Yahoo
Rankings are not decided by PageRank. Yahoo do not have anything like PageRank....optimizing site accordingly will get you rankings eventually.
yahoo has it's own version of pagerank that used to be available publicly...no longer the case though , but they still use it for their rankings.
yahoo gives more importance to domain name.If you have a domain name which correctly describe your website,You will get a good rank