When you go to run an Adobe Application such as CS5 on your new 10.7 client it will not run and will ask you to install JAVA Runtime.
Adobe have a article about this http://kb2.adobe.com/cps/909/cpsid_90908.html
The catch is the on some company networks that use a software update server this update may not be available yet
Solution : Download this directly from Apple. As of 9th January 2012 it was available from here.
I would suggest checking if a more recent JAVA runtime (JRE) is available if using this link in the future