Joshua-Tree-Hugger, Ireland is set for at least 2 shows, as the second date for Croke Park is being held for June 25th. The 2 dates there were originally being rumored for June 25-26, now they are 24-25 which means they now could add a third night there on June 27 or even use that date for Belfast, which Bono has been quoted as saying that he wants U2 to play there again.
As far as being able to order second nights through u2.com, the only way that would happen is with the cities where a second night is already announced (Chicago, East Rutherford, Boston) because these cities will go to 3-4 shows each, or if U2 decides to hold the second night for sale 1 week after the first show sells out. Holding the date for sale a week later is more likely to occur with the European stadium shows than with the US arena shows, where in most cases, they will just add the second show minutes after the first one sells out. It all depends on the speed in which shows sell out. Promoters sit on second dates in cities and guage the speed in which the first sells out. If these US arena dates sell out in 15 minutes or less, you should expect them to put the second date on sale right after. If it takes more like an hour or 2 to sell out, they will feel the momentum is not there to put them on sale right away and will hold the sale of the second show until they can have a public announcement that a second night is going on sale. This usually means they put it on sale 1-2 weeks later.
