I wonder if Ajax crawling suggested by Google is also applicable to Yahoo and Bing. It seems that only Google can crawl my Ajax page after I implemented that.
To my knowledge, there has not been any word from Yahoo/Bing that they support crawlable AJAX. I'm not even sure that the specification has been finalised by Google.
So do not count on your AJAX content being crawlable by anyone other than Google at this time. It may be a good idea to create individual pages where possible for the other search engines.
It is possible that Bing has adopted Google's scheme.
The first result is AJAX-enabled web page with "#!".
According to my tests Bing/Yahoo support hashbang Url (#!), but they do not support pretty Url (pushstate) with the meta tag fragment has Google does.
(meaning you have regular url,
host/Category/Product/, but the crawler will crawl
host/Category/Product/?_escaped_fragment_= which enable you to serve a static html snapshot)
This is quite an issue since, as far as I know you cant mix pushState and Hashbang.