OpenOffice and Microsoft Office

[aldo albanese]

Hi,
My company is 95% windows.  I was planning to install OpenOffice3.2 on new desktops.  I was wondering what kind of issues I will get myself into:  These are few of my questions:
Compatibility issues between OpenOffice and Office 
Learning curves for my users that are not to technical savvy.
Business acceptance of this new product
User Training, more helpdesk tickets?
Please let me know if you have implemented something similar in your company and if you were successful with this implementation.

Thanks,
Aldo