sanjaysakhrani, you may be right about those stories, though.
I don't see why they would use those three different GA blocks in such a small venue, despite the restrictive fire codes. If they indeed use the 23,000-person arena setup, that means they'll be using blocks on a GA floor space similar in size to the Oakland and San Jose Arenas here in the US, which would be rather absurd, I would think, especially if they build the two B-stages used on the outdoor shows rather than the Ellipse.
Regarding the larger stadium rumor, considering the Saitama Super Arena's flexibility to stage large or small concerts, it's quite possible that U2 planned initially to hold their concerts in the 23,000-person arena setup, but now changed the last two shows, or even all three, to a larger configuration, with space for up to 37,000 fans, due to the high demand for tickets, though this would screw up the seating arrangement for those who initially thought they were buying seated tickets close to the stage (like what is happening now to some Aloha Stadium ticket-holders).
I don't see how they would do that between shows, though, considering they would have to rearrange the entire stage to fit the larger setup for the second show, which they won't have time to do, I don't suppose.
However, since Clapton is playing there on December 2nd, in between U2's second and third shows, U2's crew will have to set up their stage from scratch anyway (unless Clapton uses it) for Dec. 4th, so maybe they'll hold that concert in the larger configuration.
--- By the way, the weird thing about Clapton's Japan tour is that he's playing 8 shows at Budokan, then squeezing in his one gig at the Super Arena in between the U2 shows:
http://www.whereseric.com/tour/eric-clapton-tour-calendar-2006-2007.html
What are the chances the two entities will meet at some high-class Tokyo nightclub after one their concerts?