X4 is more then a sure thing
for those who think it isn't happening, once the final numbers come in and Xmen has made roughly 250 million (my guess, if this second weekend hadn't dropped quite as hard i would have considered it a lock for 300, all in all, there still isn't a big market release till superman returns to really knock the steam out of xmen so you can put up at least 30 million the next two weeks like this one on there) and also another 180 or so over seas, so your looking some where in the neighborhood of 400 million for a movie that many comic fans(excluding myself) did not think was a well made movie
when they look at those numbers, the general public reaction (which is good) the super fan reaction( which was mixed at beast) and think if they can at least keep the general public happy they will continue to make money, and if they can make the superfans happy they will make tons of money
obviously i doubt they will spend another 200 million, but it will still happen probobly with a budget of 150 (which is still a **** load that they can make a cool flick out of) with the proper time and preperation...so that means for a 2009 release they have to announce it by the Fall, which i would be surprised if it happened, i think they will wait till christmas DvD sales, once those numbers come in they will annouce it around January, Febuary 2007, pre production will start scripting casting financing budgeting marketing, the works that should be done around the Fall...
depending on when and where they start filming they might not start till the spring if they want to film in vancouver again, then they will probobly spend the usual 3-5 months filming, ending august september something like that 2008
if they are shooting for the memorial day 2009(which they should they would be the only movie franchise with 4 movies in one decade i think all making about 400 million in total box) that gives them about 4-5 months of post production, which depending on the CGI and what they did in pre production could/should be enough...
i will say Memorial Day 2009 at the very earliest
i think 2010 would be likely too
depending on if the spin offs flop it could be even 2012-15 before we see another one and by then it might be batman begins route anyways
but point is...there will be an X4, XBegins, X-Men continues movie or what ever, there is no reason to shut the franchise down, within 7 years there will be another XMen movie..
if batman got another movie (it was that franchises last chance, because most thought it was dead) xmen has at least 1 more movie, if not 3 or 10