I never stopped using Now Up To Date and Contact 5.3.2 even though I upgraded to Snow Leopard and Snow Leopard Server. The Now Server continues to chug along both for intranet and Internet connectivity. The printing functions are messed up by the new Snow Leopard approach to printing, but things appear just fine on screen.
The big downside, of course, is the lack of all of the fancy bells and whistles Now X was supposed to (and never did) provide, like iPhone syncing, etc. Maybe someday someone will write an iPhone App that just connects to the Now server and then displays the data in a usable way.