ULTIMATE WOLVERINE VS. HULK is simply another example of Marvel being so desperate to attract the "cool kid" writers from Hollywood that they'll throw them ANY project under the sun, regardless of the fact that for most, comic writing is clearly their 'hobby' job and they're under little obligation to not let issues fall very, very late. Marvel made this mistake with Kevin Smith and hasn't learned since.
Of course, when the EIC of Marvel apparently has no idea of how his day-to-day schedule will compound his ability to write/draw a monthly mini series, perhaps expecting them to be more efficient in planning series elsewhere is asking a bit.
The bottom line is the first two issues sold well. They got your money. So its a success. Issue #3 will come out on the 11th of "whenever the hell we feel like it" and it'll sell well too, and whatever. The reason why Marvel is so quick to spit out books without seeming to be able to fathom whether they'll ship on time or not is simple; they want your money, and to strike while the iron is hot. One could say that some "setbacks" are impossible to predict, but on the other hand, a failure to be able to predict certain setbacks in the current comic medium, espeically when things like late books are hardly a "new" problem, is inefficient at best.