(I hope spoilers are okay... I'm going to try to explain it from the beginning, assuming you're not already familiar with Haruhi.)
There's an anime called "The Melancholy of Haruhi Suzumiya," based off of a series of Japanese light novels. The first season, 14 episodes, came out in 2006, and was wildly popular.
For three years, the second season has been in high anticipation. There were a lot of strange hints, false leads, and confusingly contradicting reports. Finally, it is airing right now in Japan.
Now, the whole Haruhi franchise is known for being unconventional and confusing. The first season's episodes were aired anachronically (out of order). The second season, 28 episodes, is a rebroadcast of the first 14 episodes in CHRONOLOGICAL order, PLUS 14 new episodes to be mixed in in between to complete the timeline of events.
So far, 10 old episodes and 8 new episodes have aired. The weird part is... 7 of the new episodes have been, essentially, the same.
It's been heavily suggested that this season would follow the fourth light novel of the original series, "The Disappearance of Haruhi Suzumiya" - that's the story people have been looking forward to seeing animated. Instead, what's been airing is "Endless Eight" - a seven-episode (so far) adaptation of a mere 30-page chapter in the light novels - which is getting fans really upset.
The concept of "Haruhi Suzumiya", if you didn't know, is that the titular character, an eccentric teenager, unknowingly has godlike powers to alter the universe according to her desires.
"Endless Eight" is a story arc about how the characters become trapped in an "endless recursion of time" for the last two weeks of their summer vacation. That is, those two weeks keep repeating over and over again in a time loop. It seems that Haruhi, for some reason, doesn't want summer to end - she has SOMETHING she still wants to do - so, inadventently, her powers cause time to continue to cycle until some factor is changed. And the characters can't seem to figure out what she wants.
The series of "Endless Eight" episodes, therefore, are literally portraying the SAME EVENTS over and over again. One episode: phone call, swimming pool, festival, cicada catching, part-time job, stargazing, going to bed without finishing homework. Next episode: phone call, swimming pool, festival, cicada catching, part-time job, stargazing, going to bed without finishing homework. Seven whole episodes so far of the SAME EVENTS.
However, it's not just a lazy rerun of the same material. The producers are actually re-animating and re-dubbing the whole thing, over and over, with subtle differences in details, angles, outfits, etc. Fans can't understand why they're putting so much effort in something that is being received so negatively, and wasting precious episodes of the new season. Some have dropped the show completely. They say it's "epic troll." Others say it's pure innovative genius.
Why is it, really? Because Haruhi is crazy. That's what she's famous for. They're doing daring things to stir up the popularity (and hopefully build tension toward what the much-awaited main storyline of Season 2 will be). See? Even you're asking about it and being introduced to it - which means people are talking about it and the hype is working. xD
Since it's called "Endless Eight" and next week's installment will be the eighth, people are expecting the next to finally be the conclusion of the story arc... but of course, that's not a guarantee.
It's undoubtedly aggravating, and yet I for one am still quite entertained and amused by the whole thing. In fact, the annoying repetition kind of has a purpose. In the show, time has repeated a whopping 15,527 times, and one character (Yuki Nagato) actually REMEMBERS it all consciously. For viewers to at least experience it seven times creates audience sympathy for Yuki along with a reason not to complain ("you think you're sick of it? JUST THINK OF POOR NAGATO!").