Justice League 3000 may be set in the future, but it features some seriously old school story telling.
Many contemporary comic book writers write for the trade collection. They tell stories in 3 to 6 issue arcs that are best read in one sitting rather than in monthly installments. The one concession to the periodical nature of the format is the use of "last page reveals" in which a shocking twist is revealed on the last page of the comic, inspiring the read to buy the next issue.
Comic writers of an older generation followed a rule of "every issue is someone's first issue." Each issue would include some monologue or dialogue explaining the premise of the story and recapping the previous issue. In Justice League 3000 Giffen and DeMatteis stick rigidly to old school exposition. Each issue includes a scene in which characters explain the premise of the series, which is rather convoluted and requires a lot of explaining. Then another scene follows in which the JL characters explain how they are different from their past counterparts. This process eats up about 5 pages per issue. It may be useful for a reader who picks up issue 3 without having read the previous issues, but in collected format it is excruciatingly repetitive.
The story is about a brother/sister team of scientists who resurrect the legendary Justice League a thousand years in the future to fight omni-powerful tyrants that rule the galaxy. How the resurrection is pulled off is actually quite clever and I wont spoil it. The story is not bad, but at times I felt like I was reading a comic from the 1970's rather than a story from the year 3000.