In the past I have used my hackintosh to connect to corporate email servers, and I've used the Enterprise Vault OSX Add-in. It's something though that sometimes lags behind from a Symantec point of view.
When new versions or rather Service Packs of Office for Mac are released, and, when new versions of OSX are released there isn't the general 'rush' to support the changes. I suppose it's down to the amount of effort versus the number of users; there are just far fewer OSX users who need Enterprise Vault connectivity than Windows users. There are also far fewer testing resources (hardware and people) when it comes to OSX.
That being said it is good news! I spotted a note on the Connect Forums which says that OSX 10.9 *is* supported.
I've not tried it, yet, have you? Let me know in the comments below.