For years, I've always thought about all the preliminary stuff that is seen in both test versions of AC DDR games and also pre-release builds of the CS games. I think we should gather up all known information (and possibly add to the wiki.)
The 2 CS games that baffle me the most are ULTRAMIX and EXTREME US, simply from all of the preliminary screens.
Ultramix:
Biggest things to note are: Interface, icons at top left, the "sections" inside the arrows are transparent, real-time grading, 2 combo counters...and AUTOPLAY(!!) on the 2nd picture.
Also all of those characters were scrapped.
EXTREME US:

*sigh* It was SUPPOSED to be this way...and we all know ONE of those songs was cut (and it shoulda been in the previous game anyways.)

Marvelous in regular gameplay (missing in Final...also w/o the double L crap). Also kanji removed from difficulty bar, and the font was fucked around with just like in DDRMAX2.

We didn't even get any of these characters in the final product... ;_;
Also I know that plenty of games have had songs in them that were cut or removed around...(everything from 1st Mix to SuperNOVA.)
Ok, so, anyone know of any other things that have been scrapped in DDR games?