Not too long ago, there was a Pojo.com Yu-Gi-Oh! Forum posting on a supposed "leaked" March 2010 banlist, that was quickly taken down. Fortunately, google has a cache version of the forum posting:
http://74.125.153.132/search?q=cache:BP1q79LV9pAJ:www.pojo.biz/board/showthread.php%3Fp%3D16644074+pojo+latest+rumoured+march&cd=1&hl=en&ct=clnk&gl=sgI did not expect the banning of Brain Control. It is hardly ever used in Gladiator Beasts, Dimensional Eatos and Lightsworns so those 3 deck archetypes will not be affected much. Every other decks most probably main one.
Brionic will be most definitely be limited in the TCG banlist. However, I think limiting Black Whirlwind will affect Blackwings badly so I think semi-limiting will be more suitable. Chaos Sorcerer's limiting is possible. I don't know about Beckoning Light to 1 but it can be a powerful game-ender if enough cards are milled, so maybe that's the reason. Burial from a Different Dimension's limiting will be to cripple Vayu Turbo and Zombies, although Adam Corn's Diva Zombies only used one copy in the recent SJC Los Angeles. Magician of Faith to one will be an interesting card for Lightsworns to use. I think Gyzarus to 1 will not affect GBs much as they can tag Gyzarus out to tag back again for its effect later.
Semi-limiting Bestiari will make GBs more competitive again although the limiting of Solemn Judgement has weaken the deck severely. Charge of the Light Brigade to 2 will slow down Lightsworns. Cyber Dragon and Emergency Teleport to 2 is quite broken, I do not think it will come true. Book of Moon is a very useful card but I think there isn't much of a difference between using 2 and 3.
Un-restricting Snipe Hunter might be to help sell the upcoming Infernities cards. It is also good for Zombies. Lonefire Blossoms to 3 may be possible as Plants are not competitive yet.
Those were the "leaked" banlist cards. I really like to see Bestiari put to 2 but let's wait and see when the real list is revealed next month.
