It's obsolete for ME.
The only Ultimate books i got into were Spider-Man and Avengers...The chronic lateness of Avengers made me not want to get involved with volume II of that book, and USM just started to bore me to tears some time around the Carnage arc...
So that, and the recent upswing of the 616 Universe, with Civil War, Annihilation, and Planet Hulk, have made me completely lose interest in the Ultimate Universe. I doubt i'll pick up an Ultimate book ever again.
Good God, have you been rummaging around in my head, Captain? I felt the exact same way about Ultimates--vol. 1 was good but not worth the delays, so I ditched it about 2 issues into vol. 2 because tardiness became a problem again. I also quit reading USM right around the point where Ultimate Carnage killed Ultimate Gwen Stacy because I felt it had lost all of its momentum.
Anyway, I think the Ultimate Universe is pretty much obsolete if you look at it based on the stated purpose of the line. It really has outgrown its usefulness as a jumping-on point for completely new readers since, as others have pointed out, it has hundreds of issues and over half a decade's worth of continuity behind it now. That continuity--plus the Ultimate Universe's
far greater penchant for disruptive delays--has led to all the same problems and glitches of the 616 universe, which the line was trying to save readers from to begin with. Even Marvel itself seems to have abandoned the Ultimate line as the ideal introduction for new readers; that title seems to have fallen to the all-ages-friendly Marvel Adventures line now. All that said, however, as a source of income, the Ultimate universe is still very much viable thanks to its large fanbase, so I don't see Marvel actually canceling the line anytime soon.
I gave up on the Ultimate universe a long time ago, myself, and as the 616 comics have grown, I've felt more and more justified in doing so. The 616 universe is richer and more compelling than it has been in a long time now. Civil War was pretty mediocre but, like Avengers Disassembled and House of M before it, that mediocre event seems to be leading to some interesting new comics. If we keep getting spin-offs like Young Avengers, the X-Factor revival, and Avengers: The Initiative, I might almost be glad to see crappy events coming down the pipeline in the future. Not to mention things like Annihilation and the upcoming magic event, which are reversing Joe Q's earlier mandate to scrunch the Marvel universe down to a myopic street-level perspective and expanding it back out into the sprawling landscape of the Infinity Gauntlet era that I loved so much.
Of course, I also think the 616 universe owes a bit of a debt to the Ultimate. I don't think the former would've come so far if the latter hadn't proved through high sales that comic fans are open to new interpretations of established concepts. New Avengers, for one, probably would never have gone through if not for the Ultimates and, even though I'm not a fan of Bendis' take on the Avengers, the Avengers line has irrefutably been reinvigorated because of NA.