Publish Lync and Exchange 2007/2013 on same forefront TMG array.

Hi,

I have a forefront TMG array consists of 2 servers,  currently publishing Lync 2013 services. I wanted to publish Exchange 2007 (Exchange 2013 in future)  also using the same array. 

Is this doable?

Any  known issues? 

What are the steps to be followed?

thanks for your help..

regards,

Arif