My piece of cake.
1. Ability set AVS window sizes from preset code. And flag in settings to disable this.
2. Arrays in some manner. One wrote about store\recall pair - this is same as arrays. But arrays are greatly needed. Of course arrays will require function to quickly fill them by data.
3. GLOBAL VARIABLES! I read current wishlist but I wanna tell again - this MUST HAVE. And I'd like add one suggestion here - not exactly global. I suppose better create some "Misc" function, for example "Variables". If it is included to "Main" section - then all variables listed there are global. If is included in "Effects list" - then variables are global for just this list.
4. Simple effect "Glow". It is quite hard to implement it on AVS code. But it looks very nice - like light around shining object. Of course it must have controls as obvious glow (in Photoshop) has - at least color, size, opacity.
5. More editing options. Search\replace in code. Multiplie effects selection in tree window. Ability to export\import to text file. May be finction "Import <textfile>" (Ok, ok, I understand...)
One thing looking as bug. Ok, I use program TClockEx. It's window replaces standard Windows clock. Very useful and popular program. But when I switch AVS to fullscreen - then TClockEx window flashes twice per second over AVS. Quite ugly. I DID NOT see same effect in any other program in fullscreen mode - not in Win Media Player, not in any MPEG-1\2\4 video player. With WinAmp I have to turn clock off when I like open fullscreen AVS.
And finaly dreams... I dream about interface to OpenGL... :-D