But seriously they started off as rumors. The first hint was when Capcom released MVC2 on Xbox Live, more optimists took it as Capcom's way of testing the waters. The game sold pretty well actually. Then rumors started flying around that MVC3 is being developed and that it will be revealed soon at Captivate. It was unveiled with a godlike trailer that got everyone hyped but not many characters shown first.
They started unveiling characters through silhouettes, most people figured out most of them. Then the reveals started happening and it was a roller coaster ride. A ton of fake reveal lists popped up but the original Lupinko list was the real list and about 3/4ths way Lupinko was vindicated when it was learned that Jill and Shuma are going to be DLC characters (as that was a completely left field guess that no one else had). There was a shit storm over it but it soon subsided. Lupinko also became legendary on GAF. Some characters people liked, others didn't and of course the holes were pointed out as always (no MM, no Strider etc.). People also complained a lot about X23 and She Hulk being a waste of slot because they would be too much like their counterparts. Most people warmed up to the cast by the time the game was released. It was a fun ride.
The lead up to UMVC3 was even crazier. Lupinko started mad teasing about a potential expansion pack and about a few weeks before its rumored unveiling Lupinko started busting out teaser riddles about characters that would be in the game. The first two were easy, it was Phoenix Wright and Strider but most after that were extremely vague. The forums went completely ballistic trying to guess riddles and doing reach arounds until they something stuck. Most of the internet had themselves convinced that Apocalypse, Carnage and Jubilee were confirmed from the tweets. Lupinko started to give more hints that disproved those characters but at that people had worked themselves into a frenzy. Characters were eventually revealed and there was a shit storm. No black characters, no female characters, no Spider Man villains, no Megaman etc. Some characters of course people liked and most of them people warmed up to by the time the game was released but the lead up to it was a massive roller coaster ride. Also the timing of the expansion was bad, it came out way too early and was announced very quickly too.