^They're likely unlockable secret characters.
EDIT: More from Iggy:
Mary and Ash have been added to KOF MIA.
They are making a PS2 version, and the game was played on PS2.
interface makeup : reversal, gauges, select screen , loading screen have been redone.
The loading are as long as the PS2 MI2.
The game is 40% complete, scheduled for early 2007.
Each normal and alternate outfit has 4 colors.
There is a "?" box near Jivatma, and it will be "a character nobody expects".
The old characters haven't been changed yet, but they plan to change around 1000 small details to them.
The BC sabaki is easy.
Kof 98 UM will have the boss team, based on the 96 version with new moves.
Geese's reppuken doesn't fly, and his deadly rave is just a normal rambu (you don't have anything to do once the first hit connects).
Krauzer has a new throw miss animation, gigantic cyclon, and other moves.
BIG has been changed quite a lot, looks like his NBC version.
Their winning screen has been drawn in the 98 art style.
The typos (ultimate MA"TC"H) have been corrected.
Two boxes near Shingo, two other near Rugal. (Kasumi Eiji Goenitz Orochi ?)
The character and stage select screen have changed.
A new ultimate mode has been added to the advanced and extra modes, probably a customize mode. The extra mode has been changed : when you charge you gauge to the max, the gauge is stocked and you have to activate it. There is a roll cancel ?
http://ffl.sakura.ne.jp/
select screen and Krauzer.
Game should be released around spring.