A Hypothetical Office Question? (MS Office/Open Office)

I understand that if a user installs Open Office on a machine with conventional Office 97-2003 that Open Office will use its own suite of products for each application. (Unless the user ops to use Office to open the applications by unchecking the corresponding application boxes during Open Office's installation.) But if a user chooses Open Office as the default for applications on a system that also has Office 2007 on it, how does Open Office deal with this if the OO applications remain checked as the default?

Does the current version of OO even understand how to DEAL with the new Office 2007? I understand that OO can not read docx documents, which is the default for Word 2007, (although this can be easily changed back to doc.) I found out that Open Office 3.0, scheduled for release this fall, will be able to read docx documents. What's so great about docx docs anyway?

Using my example, assume this situation on a new Windows Vista machine. (fresh installs of each program or Office 2007 OEM (factory installed.) What behavior would be expected here?

Jack