I wouldn't say it needs to go myself. Excellent coverage, only one "true" counter; but we've been through this a million times before. Landorus suffers from 4MSS, which may make it unpredictable, but it also makes it possible to wall depending on what it lacks. Its Speed is good, but lacking compared to many of the other monsters roaming in OU, allowing it to be easily checked by a variety of commonly used attackers. Don't get me wrong. This thing is amazing. But broken? Even Mega Metagross, which is the closest thing to a real life tank in OU managed to stay. I don't think it needs to be banned.
That being said, if it ends up getting banned, I don't see the metagame changing drastically. Landorus-I doesn't keep that many things in check, it's not like Aegislash which severely limited many otherwise perfectly good mons. The hole Landorus will leave behind will not be exactly gaping. Its ban will not signify any big changes in the metagame.
4MSS is indeed a problem which lets the opponent the option to scout for Landorus's set. The problem is the fact that Landorus-I 2HKO almost the entire metagame and can set up CM or RP while the opponent is trying to figure out what set it is. Greninja had the same problem but it could not set up on switches. And it still got banned. Not that I want to compare Greninja to Landorus-I but just to show how the 4MSS can sometimes help Landorus-I rather than hurting it.
With Landorus-I gone, Do you think it would affect team building? I mean this thing is designed to break both offense and defensive teams depends on its set. This might be just me but I thing he has part of the fact Balance teams are getting more popular these days.