At first this one is fantastic program. I as a graphic designer don't know any script codes, action codes or something else. But with Catalyst I can create incredible, awesome, interactive projects. It's fantastic!!! 
So, what in my opinion must be added to next Catalyst version 
1) Gallery. Cause now I create my own portfolio site, ant there is no function for comfortable gallery. It will be very good, if in next version we will have a some gallery's templates.
2) More than 20 pages. Cause if you want to create some interesting interactive project, 20 pages is too small... 
3) Button function. When you put (with no push) your cursor on button it automatically slide to side (up, down, left, right - on witch button you put your cursor).

4) Timeline functions. It will be good if in timeline we can chose FADE IN or FADE OUT, not automatically chose.

5) Zoom function. Like in PS AI ID, wheel+alt=zoom. Because its not comfortable to push ctrl+/ctrl- or chose a zoom tool.

6) Version for

I'd like more complex buttons, like a drop-down button. For example, to edit the text that I'm writing right now, there are "Font family" and "Font size" drop-down buttons -- when you click the upside-down triangle, a list of options (scrollable) cascade beneath it. It's possible to use Custom Components and/or maybe Data Lists but it's a bit cumbersome and time-consuming.