Not tons of work -- I am planning to do it. The only things we use Scriptaculous for right now are drag-'n-drop sorting and fade effects. jQuery and the interface library can handle those even better, so I want to switch.
Yea, the next version will have the switch. But ZenPhoto is a community project, if you figure it out on your own you are always welcome to post it in the forum or trac.
General question: I currently use Prototype (and Scriptaculous to a certain extent - though I have no use for fancy fading and sliding - I just change the page). What are the big advantages of JQuery over Prototype? Enough for me to change my Javascript in all my work?