Yep, that is indeed something we want to have too! We have a bunch of new nodes ideas on the pipeline, but we wan't to be extra careful to not bloat the interface just yet (until we come up with a clever filtering system - it's important for us that the interface always feels "comprehensible" at a first glance). But obviously we want to know what the community think it's important and prioritize that first.
That said, for this particular case I have 2 ideas in mind...
One I think is what you suggested, a list with a trigger - every time it receives a trigger input, it steps to the next item of the list, looping when it reaches the end.
The advantage of the list is simplicity - there is no need for intermediary nodes, you just add the items and plug it directly to whatever you want to control.
The other idea is to have a node that is simply a "Counter.
It would have 2 inputs - trigger and step. It's out value would be incremented by the value of step every time it receives a trigger.
The counter could then be connected directly to an ordinary list - and possibility to a "modulo" node to make it loop (we have a bunch of Maths nodes on the works).
The advantage of the counter is it's transparency - from an educational point of view it gives the opportunity to tackle a few mathematical concepts, and it would actually help understand how the "original" list works.
What do you think?