-allow internet race and co-op without having to use programs like XJJ2 or JazzForce
-fix internet co-op so guests can get hurt too and endlevel works
-fix palette entries for the freakin' Carrot Bump
-fix Lori so she can use the copter
-add Lori Start Pos event
-fix Echo event so it doesn't last until you shut the game completely if you have quit the level with echo turned on
-add "Delay" option to Ambient Sound event, which would set the time between two sound cycles
-make a posibility to pick a boss music from your own, including other supported mod formats than j2b
-fix the flag bug (of course)
-fix Swinging Vine event, so you can't go through walls while swinging
-fix rock events so that they're more reliable (it's annoying when they don't fall without any reason)
-allow bigger mod files
-make more possible effects for textured background (in JCS it looks like they wanted to make more than just Warp Horizon), like for example swirl (texture turning around the screen center, like in one of the backgrounds in MK3)
-fix Rocket Turtle event, it would be a very nice boss
-fix Twiddle Boss or remove him for sake of event space
-fix Fast Feet
-allow to create a time limit in a SP level (as an optional thing), without having to use weird tricks
-I think that there should be a character with opposite abilities to Lori (double jump and uppercut), maybe Eva or Razz?
-there should be someone else instead of Eva to unfrog you when you're playing as Lori... at this moment, it's EVIL
-make an ability to use your own custom j2v
-fix Lazer Shield event, so in SP it appears as a pickup monitor; in MP the one who uses lazer shield should be automatically banned

That's all that came to my mind at the moment. I'll probably think of a lot more later...