Microsoft’s Mac unit is launching a private beta in February that will bring Office collaboration to Mac users. The Cocoa based app will make downloading/uploading shared files easier and will be available as a free upgrade to current Office users later in the year.They’ve also done some work behind the scenes on Entourage, improving its compatibility with Exchange Servers. A public beta will be available later this month, so long as you can stand using Entourage in the first place. It all sounds like a pretty standard response to Apple’s iWork announcement to me, although I’m sure it’s something they’ve been working on for a while now.