Sure.
Essentially, I live in a country where mobile broadband is very pricey, so if I am travelling, or simply out on a client's site with my macbook, I do not want to pay mobile broadband prices for any file movement. Rather these just go into the holding folder, and when I am connected to WIFI with some time, I kick off hazel to do her wonder!
Use cases are for me, identical to those of the Iphone. All the IOS Apps I have that move files in someway, get books, get music, check a book catalog etc..have this setting (e.g. only send files/download from any app store etc. if on WIFI )
My email app has this e.g. to do not download attachments unless on WIFI.
Hazel just runs, so I guessed if I had a conditional statement like these IOS Apps, she could get busy doing the correct assigned task, beautifully.
This style of condition check means for me, my workflow is more robust. I do not have to think about what to do, just I know when I connect, there is always stuff to go up/down. Secondly, when I am working at home, on own WIFI, or at a public library, I do not want things queueing (like on a to do list), they can just get done immediately.
Movement of files between my macbook and cloud happens all the time. Quite amazed at how often actually something is going up or coming down. My main drive is in the cloud and my local is my mirror as I travel alot.
When I am in USA, the mobile broadband is much more affordable, or public free wifi is readily available so one is not so concerned.
Do you by chance know the AppleScript to check network status? As I could create a workflow to call AppleScript as a workaround.)